Odd wiring in 20 year home (another wtf) - return/white grounded in switch box???

[Charlie]

I'm in the process of replacing a bathroom vent with light. I mean, how hard can it be? :) In so doing, I have encountered some wiring that has me puzzled as to safety and function.

What caught my attention was that I have a single, 2 wire w/ground running to the vent. For two circuits? Hmmm. Let me see if I can describe this.

Power to the switch box is supplied by a single two wire w/ground. The black wire is daisy chained to both single pole switches. The white wire is connected to ground in the switch box (???).

Now things get weird. The 2 wire w/ground running into the ceiling has the following connections:

- the black wire is connected to the fan switch and up to the vent fan;

- the white wire is connected to the light switch and up to the vent light;

- the ground is tied into all the other grounds.

Up at the vent, we see the connections described as above; however, the ground is left floating in air. The weird part is that the vent white wires for the fan and light are connected together (???).

I don't see the return path such that this would work. Is there something I am missing?

Appreciate any feedback to this mess.

[Charlie]

Okay, I went back and checked the original connections... again. As I described it, there was no return path, and hooking it all up proved it - nothing worked.

So, the ground at the vent is not floating, it is tied to the return. Near as I can tell, it's a cheap way of avoiding another run to the hardware store for some 3-wire or another run. Am I looking at a short-cut?

cg

[RBM]

Not a shortcut, a non professional, dangerous mess. Get a piece of 14/3 with ground and wire it correctly

[Charlie]

roger that, rb. But, doing web searches didn't yield anything other than ground loops be bad for audio equipment. Why particular dangerous?

[RBM]

The only way it could work, with a two wire cable, is by using the ground as a neutral, thereby eliminating the safety conductor, and allowing the metal body of the unit and anything that may come in contact with it, to become part of the circuit

[propman]

This point is weird enough! ;-)

[Mark]

The other way to make this legal is to abandon one of the switches and tie the light and fan together on the other: White to white, black to black and ground to ground.

If there is another light in the room and you really don't need the light in the fan, you could just wire it this way and then leave the bulb out so the switch only operated the fan. I wouldn't leave the entire light disconnected or the next owner will end up in the same kind of quandary - what the heck is going on with this wiring!

[JIMMIE]

Sounds like someone is using the ground wire for a neutral. This happens a lot usually in the case where someone adds a vent/light where only a light was or adds a ceiling fan/light combo where only a light was. This happens fairly often when someone is sprucing up a house to sell.

Jimmie

[Tony]

I never heard of using a ground for a neutral being called a "ground loop". Maybe it's a proper term, but I've never heard of it. A ground loop as I was taught can occur with audio equipment when different equipment hooked up together use two different paths to ground in the panel. You get a 60 cycle hum.

[dpb]

Tony wrote: ...

Because it isn't...as your post goes on to state.

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