Fluorescent lights hate it . You can burn out the ballast the heart of the fixture by repeatedly switching them on and off . Same with compact fluorescent lamps , for similar reasons . Fluorescent lights no longer contain a starter , but they are still sensitive to frequent or rapid cycling . LED ' s can be designed a number of ways , but they all contain a considerable amount of driver circuitry . They probably won ' t die as fast as Fluoro drivers since they don ' t handle power in the KV range , but there are risks . This doesn ' t matter for the LED diodes themselves , but the capacitors on the driver board may not hold up to repeated abuse of repeated chargedischarge cycles over a short amount of time . Incandescent bulbs are most vulnerable when starting from cold , so in my experience , they are most likely to burn out when turning on for the first time in quite a while . I have a theatre background , and it was usually that first powerup where you ' d hear lamps pop . I ran several effects through the years that involved flashing lights and after initially warmed up , they were quite tolerant of steady flashing , as long as the interval was enough to keep the filament warm . But it was always that first startup of the day that got them . The other side of the equation is the switch itself . Every time the connection is made or broken , a small electrical spark can occur on the metal contacts inside the switch . Over time , this can cause carbon build up andor pitting , which increases resistance heat . This can eventually lead to the switch ' s failure . This process can be sped up by the fact that when you quickly cycle a switch on and off , you may not complete the full length of travel each time , which can increase the amount of internal arcing . Sorry if this is not very ELI 5 .