Anyone good with residential electrical wiring?

[PTmowerMech]

I was going to replace an old light socket today. It was just sort of hanging by the wires. The LED I bought for it, wouldn't screw in far enough to connect. (just a normal bulb screw in type), So I thought I'd change out the whole thing. I'm fairly knowledgeable about wiring, so turned off the light switch, undid the wires, and decided to check which one was hot. I've repaired some other wiring in this old house, and found the white was the hot and black was neutral. And sure enough it was the same. Except there was an even bigger problem. With just the light switch off, I was still getting current through the white wire.
So here's how the wiring went. From the breaker box, it went up through the attic where it was spliced. One went to the plug by the washer, the other went to the light socket first, then onto the switch.
I screwed up when I unhooked the wires, because I was under the assumption that the wiring came through the wall to the switch first, from the breaker and then up to the light.


I can't figure out how on earth he got the light switch to power the light, when there's only two wires (a black & a white) going from the splice, through the light socket and then ending at the light switch.
I have three wire nuts laying there when realized, something ain't right. And that's where I got lost.

 

[ILENGINE]

Not unusual for the lights to be wired on the hot side of the switch in old houses and then use the switch to break the circuit on the neutral side. What color wire is connected at the breaker to feed that circuit. Is black connected to the breaker or the white wire. .

So potentially you could of had a white from splice connected to the black at the socket and then white wire at socket connected to white wire going to switch. and then white and black both connected to their separate connectors on the switch and then the black is wire nutted to the unused black back at the light.

 

[Rivets]

If it were me I would go buy one of these AC outlet testers. They quickly tell you how the outlet has been wired. When I find ones like yours i rewire them properly, starting at the breaker box. Like IL said many of the older homes were wired this way, especially in rural areas, or someone who didn’t know what they were doing. Takes a bit of time, but saves a big headache and sparks down the road. https://www.homedepot.com/p/Recepta...VLQ1EEAQYBSABEgKA4_D_BwE&gclsrc=aw.ds#overlay

 

[StarTech]

Wait you run across some my wiring...Drop a 240 vac line (three wire with safety ground) and split it for full time wall plug use and a switched light circuit. Or drop a 240v line to wall plug but have two 120v 15/20 circuits at at the plug. All while having two separate breakers on the 240v line

 

[PTmowerMech]

Not unusual for the lights to be wired on the hot side of the switch in old houses and then use the switch to break the circuit on the neutral side. What color wire is connected at the breaker to feed that circuit. Is black connected to the breaker or the white wire. .

So potentially you could of had a white from splice connected to the black at the socket and then white wire at socket connected to white wire going to switch. and then white and black both connected to their separate connectors on the switch and then the black is wire nutted to the unused black back at the light.

That sounds about like what was going on. I wished I had taken a picture of this before I started pulling the wire nuts off.
The white wire from the switch, I'm almost positive was connected straight to the light. From what you said, and what I remember, this is the only way it could've been done.
After drawing this picture, It makes perfect sense. And seems safe enough.


The guy who wired this house knew what he was doing. But he's the ONLY one who knew HOW he was doing it.

 

[ILENGINE]

That sounds about like what was going on. I wished I had taken a picture of this before I started pulling the wire nuts off.
The white wire from the switch, I'm almost positive was connected straight to the light. From what you said, and what I remember, this is the only way it could've been done.
After drawing this picture, It makes perfect sense. And seems safe enough.
View attachment 66163

The guy who wired this house knew what he was doing. But he's the ONLY one who knew HOW he was doing it.

That would be the safest way to wire it but i would not be surprised to find that the White hot was wired directly to the light and the switch was on the black neutral side of the circuit. I have come across enough house wiring setups over the years to know I would not be surprised that the electricians were taught to wire the light socket to the hot side of the circuit and put the switch on the neutral side.

 

[Rivets]

It would NEVER pass the building code and inspection in this part of the country. Years ago I worked with a neighbor who had to rewire 75% of his house before the inspector would OK it so he could put it up for sale. He had purchased it AS IS and never bothered to bring it up to code until he had to sell it. Plus there were a few circuits which had 14-2 wire, no bare ground wires, so we had to run new wires 14-2 with ground. Not that hard, but it was the last time I agreed to help someone repair holes in sheet rock. PITA

 

[PTmowerMech]

It would NEVER pass the building code and inspection in this part of the country. Years ago I worked with a neighbor who had to rewire 75% of his house before the inspector would OK it so he could put it up for sale. He had purchased it AS IS and never bothered to bring it up to code until he had to sell it. Plus there were a few circuits which had 14-2 wire, no bare ground wires, so we had to run new wires 14-2 with ground. Not that hard, but it was the last time I agreed to help someone repair holes in sheet rock. PITA

There was no building code when this was done. If there was, all it would've taken was a $20 and a six pack to get it approved. None the less, it's lasted for a long time with no shorts, no fires and no dangers. Sometimes building codes are just stupid.
Then other times, they're necessary. Even for people who are licensed to do electrical work. Everyone has their bad days.


I was going to run a wire from a nearby wall outlet to the switch (in the diagram), then on up to the light. But there was two layers of 1/8" paneling. And then some old wooden lap siding behind that. ( the wash room was added to what was the exterior of the house)

If this wasn't a rent house, I'd have already started rewiring it. Some of these wires are as old as the house. I may get up in the attic this fall and try to sort through some the wires, as I need more plugs in a couple of room, and relocate some light switches. But it's 110 in the attic right now. And not that important.

 

[Hammermechanicman]

Under the old NEC you can use 14/2 w gnd to wire a switch to a light you break the hot and you put black tape on the white wire to show it is now a hot. Under the new NEC rules you must have a neutral at every box. This means you must run 14/3 w gnd to the switch and use the black and red for the switch and put black tape on the red to show it is now a hot and the white neutral just terminates in the box.

 

[PTmowerMech]

Under the old NEC you can use 14/2 w gnd to wire a switch to a light you break the hot and you put black tape on the white wire to show it is now a hot. Under the new NEC rules you must have a neutral at every box. This means you must run 14/3 w gnd to the switch and use the black and red for the switch and put black tape on the red to show it is now a hot and the white neutral just terminates in the box.

LoL... My water heater is wired with just a white and a black. Both are hot. It's not even grounded.