3 wires exposed . tried to get a switch that had 3 prongs. 5309918806 demonstration tape shows 3 prongs.( not accurate). picture of switch is correct (2 prongs). im no expert but all i wanted was on off switch anyway. simple ohm and voltage reading on 2 of leads says wire these 2.. did so by putting lead thru hole in prong. and secured. plugged in and opened and closed door at least 10 times. each time light came on I felt this sense of joy that I fixed it.