mysterious wiring problem bathroom fan
mysterious wiring problem with a bathroom fan switch.
The wires are NM romex style, but are probably about 26 years old. This is a 2 gang box with one toggle for a separate light switch and one toggle for the separate vent fan.
Original simple single pole toggle switch was working and I was updating it to a new decora style single pole switch.
Original switch had black hot wire in bottom screw and another black wire coming out of the top screw that is only hot when the switch is turned on.
The hot wire going into the bottom screw was actually a pigtail from a hot "White" wire that was feeding both the separate light switch and the fan switch. No idea why they used white instead of black to bring power in.
Here is where the mystery starts: I also noticed there is a white wire in the back that is part of the wires for the vent fan and that white wire is TIED together with the ground wires.
Naturally, I separated the white wire from the ground wires, and then proceeded to install the new switch with that same 2 original black wires that were on the original vent fan switch.
Guess what, the fan did not work. However, as soon as I touched the white wire BACK to the ground wires, the fan started working again.
(1) WHAT is going on?
(2) How do I safely repair this without taking the ceiling fan out?