in the description which follows like elements are marked throughout the specification and drawing with the same reference numerals , respectively . the drawing figures are not necessarily to scale and certain features may be shown exaggerated in scale or in schematic form in the interest of clarity and conciseness . referring to fig1 , there is illustrated a portion of a condensate collection pan or water leak containment pan , generally designated by the numeral 10 , having a bottom wall 11 and a side wall 12 . fig1 illustrates a control or alarm switch in accordance with the invention and generally designated by the numeral 14 . the switch 14 is preferably characterized by a corrosion resistant non - buoyant support housing 16 including a base 18 having a generally planar first part 20 and suitably secured to sidewall 12 or just allowed to rest on bottom wall 11 in the position shown . support housing 16 includes opposed flanges 22 and 24 , see fig2 and 3 also which are joined by an arcuate part 26 having opposed legs 28 and 30 defining a receptacle characterized as a slot 32 which intersects arcuate part 26 as well as the legs 28 and 30 . slot 32 preferably extends at an acute angle with respect to the plane of base part 20 and the bottom wall 11 of pan 10 , as shown particularly in fig1 and 2 . control switch 14 includes a switch unit 34 suitably mounted on part 20 of housing 16 and disposed well above an expected liquid level 35 , see fig1 , which might occur if a water using appliance developed a leak or if condensate collected from an air conditioning system , for example . control switch unit 34 may be of a type commercially available such as sold under the trademark microswitch . control switch unit 34 includes a switch actuator part 36 and an elongated actuator lever 38 hingedly connected to the switch unit at 40 and engageable with the actuator part 36 . lever 38 may be spring biased to move about hinge or pivot point 40 in a clockwise direction , viewing fig1 , to a switch open position or a closed position , depending on the circuitry of the switch unit 34 . the switch actuating lever 38 includes a distal depending part 42 which is engageable with a water soluble tablet element 44 comprising , preferably , a biocide composition which is readily water soluble and is of a type which is normally placed in air conditioning system condensate pans to minimize the accumulation of aquatic growths or the like . slot 32 is dimensioned to receive tablet 44 and is angled in a direction wherein the base of the slot 32 a is engageable with the tablet , see fig1 . the tablet 44 is thus angled downwardly toward surface or base 32 a and is unlikely to leave the slot 32 due to vibration or inadvertent movement of the pan 10 . continuous spring pressure of the actuator arm 38 exerted on tablet 44 also aids in maintaining the tablet 44 in its working position shown in fig1 through 3 . switch unit 34 is adapted to be connected via suitable conductors 50 and 52 , fig2 , to a suitable control unit 54 . control unit 54 may be associated with an air conditioning system , for example , an alarm circuit or other apparatus in which excessive of amounts of condensate or leaking water may accumulate within pan 10 and , upon actuation of switch 14 , will result in the shutdown of such apparatus as well as possibly sounding an alarm . as shown in fig1 and 2 , the configuration of the control switch 14 is advantageous in that the parts of the switch which are likely to be in contact with condensate or other sources of water do not include electrical circuitry associated with the switch unit 34 . however , the configuration of housing 16 also assures that tablet 44 will be thoroughly wetted and immersed in liquid as it rises to level 35 shown in fig1 . in operation , the control switch 14 is adapted to be placed in condensate or liquid leakage containment pan 10 , as illustrated in the drawings , suitably connected to control unit 54 or an alarm circuit and then armed by placing a tablet in the slot 32 and in engagement with the spring biased switch actuator arm 38 , 42 . as condensate or leaking water collects in pan 10 it rises to a level wherein it contacts the tablet 44 . tablet 44 will dissolve rather rapidly allowing the actuator arm 42 to move in a clockwise direction , for example , viewing fig1 , and causing the switch unit 34 to open or close to thereby send a signal to control unit 54 which could result in shutdown of an air conditioning system or generation of an alarm signal to bring to the attention of the user of a system associated with pan 10 that an abnormal level of water is collecting in the pan . once the cause of the leakage or condensate accumulation has been corrected a new tablet 44 may be placed in slot 32 with switch actuator lever 38 depressed and in engagement with the tablet in preparation for further operation of the switch . referring briefly to fig4 , there is illustrated a self - contained alarm system , generally designated by the numeral 60 , which may include a sealed enclosure 62 within which a circuit is provided including a source of power comprising a battery 64 , an on - off control switch 66 , a momentary pushbutton type test switch 68 and suitable alarm generating means , such as a buzzer or similar audio type alarm generator device 70 . additionally , a visual indicator 72 comprising a light emitting diode , for example , may be placed in parallel with the audio alarm generator 70 . as shown in fig4 , control switch 14 is placed in circuit with the alarm generator so that when switch unit 34 closes audio and visual alarms are generated . accordingly , the device or apparatus 60 may be installed with a control switch 14 in a location where at least one of an audio and visual signal may be detected if a malfunction occurs which results in liquid accumulation in a condensate collection or leakage containment pan , such as the pan 10 shown in fig1 and 2 and described previously . referring now to fig5 , there is illustrated an alternate embodiment of a control switch in accordance with the invention associated with a unit of heating , ventilating and air conditioning ( hvac ) equipment , generally designated by the numeral 80 . the unit of hvac equipment 80 is characterized by a thermostat 82 having at least terminals identified by the letters l / f , r , g , w and y in accordance with conventional thermostat terminal markings . thermostat 82 includes a visual temperature display 83 and a visual indicator 84 for indicating a system fault condition . system also includes a so - called indoor unit 86 including a circulating fan or blower 88 and a heater unit 90 . an outdoor unit , such as a vapor compression condenser unit 92 is illustrated as being associated with the system 80 . the indoor unit 86 would also include a cooling coil , not shown , operably connected to the outdoor unit for circulating a refrigerant fluid therebetween in a conventional manner . an alternate embodiment of a control switch in accordance with the invention is associated with the system 80 and is generally designated by the numeral 14 a . switch 14 a includes a switch unit 34 a of the three way type supported in the housing 16 in place of the switch unit 34 and responsive to dissolving of the tablet 44 to move from the position shown in fig5 to an alternate position . for example , low voltage control power is supplied for the system 80 from a transformer 91 connected to terminal r of thermostat 82 and providing electrical power to terminal y when the air conditioning system 80 is operating in a cooling mode and there is a call for cooling effect . in this mode , electrical power is supplied from terminal y via a conductor 94 to switch unit 34 a and , in the position shown , power is supplied to an indicator light 95 and to a relay 96 of the outdoor unit 92 causing a conventional vapor compression compressor and condenser to begin furnishing working fluid to the indoor unit 86 to effect cooling operation . moreover , if condensate collects in a condensate pan 10 a , similar to the condensate pan 10 , to a level which will dissolve the tablet 44 switch unit 34 a will move to a position wherein power from thermostat terminal y via conductor 94 will be conducted to a conductor 99 which is connected to the terminal l / f of thermostat 82 and will result in illumination of the indicator light 84 . simultaneously , control power is shut off between conductor 94 and conductor 97 leading to the relay 96 so that the outdoor unit will cease operation resulting in loss of cooling effect delivered by system 80 , but also preventing additional collection of condensate in the condensate pan 10 a . in this way , a user of the system 80 will be alerted to a fault condition and may take corrective action to eliminate the adverse effects of unwanted accumulation of condensate in the pan 10 a . the construction and operation of the switches 14 , 14 a , the alarm generator apparatus 60 and the system 80 are believed to be within the purview of one skilled in the art based on the foregoing description . commercially available components may be utilized to construct the switches 14 and 14 a except for the housing 16 , and commercially available components may be used to , essentially , construct the apparatus 60 and system 80 . the housing 16 is preferably formed of a suitable plastic having a density greater than water and may take other specific configurations while retaining the advantages described herein . although preferred embodiments of the invention , including a switch and alarm apparatus have been described in detail herein , those skilled in the art will also recognize that various substitutions and modifications may be made to the invention without departing from the scope and spirit of the appended claims .