an air conditioning system condensate collection pan or water leak containment pan electrical control switch includes a housing or frame for supporting a switch unit which includes an elongated actuator arm . the housing includes a slot disposed adjacent a distal end of the actuator arm for receiving a water soluble tablet engageable with the actuator arm to bias the arm into a predetermined position of the switch . abnormal accumulation of condensate or leaking water dissolves the tablet and allows the actuator arm to move to a position to effect actuation of the switch . the switch may be connected to a control unit , a thermostat and / or to an alarm generator including a self - contained unit having battery powered audio and / or visual alarm devices , an on - off switch and a circuit test switch .