I was answering a trouble call in an apartment today that a pendant light fixture had come down and was hanging by the wiring.
I went to remount it, but noticed that the light fixture wiring was connected to Black and Ground. The white was unused and coiled up…and oddly, there was a coiled up unused red wire (Like for a 3-way switch, but this isn't a 3-way switch controlled light). They just used that type of cable for the wiring and didn't use the red wire – what a waste.
The light switch for the fixture is on a 2-gang box. The other switch on that box is for the kitchen lighting (which IS a 3-way switch controlled fixture). So I opened up to check the wiring in the box and think I see what's going on.
The kitchen 3-way light looks to be set-up like Wiring Diagram #1 from this link: https://dengarden.com/home-improvement/how-to-wire-a-3-way-switch-wiring-diagram
Power comes in to the kitchen light fixture and then runs over to the 2-gang box (Use that top oval in the wiring diagram for visual). The white wire going into the box is now the hot. There isn't really a neutral on this wire going into the box, right?
Well so now back to the problem pendant light fixture (not the kitchen light fixture). It takes it's hot from that white wire. But there's no actual neutral to tap into, so instead the problem light fixture uses ground as the neutral.
Does there need to be another power-in cable run to the 2-gang box for the problem pendant light fixture to tap into?
I need to check the other apartments now. Maybe this is how all of them are done.
Best Answer
OK, disconnect that pendant light until you fix the problem. you can't have a ground wire carrying load. There is no neutral in that box.
You've got to choices (well, maybe more), you can run a new feed to the duplex switch and utilize the unused white and red wires to get neutral and switched power to the pendant light after disconnecting the switch from the existing source. You could also run a new feed to the pendant light box, connect neutral to light and utilize the black and red wires for switched hot after disconnecting switch from existing source.
Remember to connect all grounds from new feeds to existing ground wires