Flight Crew Air Transport Pilot (ATP)
ATC Issue All Types
Flight Crew Became Reoriented
ATC Equipment / Nav Facility / Buildings
On final approach to Runway 25 at MTH the PAPI was unreliable.  It went from four white to white red white red (which it should never show)  and skipped white red red red.  We noticed the improper guidance and adjusted our descent angle accordingly and landed without incident.  Evaluate the PAPI for correct information.
BE400 Captain reports a misaligned PAPI for Runway 25 at MTH.