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Apologies if this is a stupid question, but I can't figure out a simple wiring setup. I have two simple switches controlling two separate lights, all on the same circuit, all in one electrical box.

There are three cables coming into the box. Left to right: First cable is WHITE & BLACK wires. Second is WHITE, BLACK, RED. Third is WHITE, BLACK. First two cables' black is joined together in a wire nut and then pigtailed into both switches (wirenut crimps 4 wires total). Red wire goes into switch one. All white wires are crimped together and are not connected to any switch.

See diagram below (note - I colored white wires in yellow so they could be seen on the drawing). Ground wires not shown.

enter image description here

My guess is that

  1. white wires must be neutral rather than hot/switch legs as they are just wired together and don't go into any of the switches.
  2. First cable with B,W wires is power in, as it is shared between two switches, and both switches operate independently (and control two separate lights).
  3. Middle cable and cable on right (two and three) are load cables to lights.

So far run of the mill light switch setup, except for... WHAT IS THE BLACK WIRE IN THE MIDDLE CABLE? I would have expected the middle cable to only have two wires, with red wire being colored black.

My question is - do my assumption 1-3 look good to you guys, and 2) what is this third wire in middle cable that's connected to what I believe is HOT/LINE directly? Can recess lights be wired with LINE, SWITCH LEG, NEUTRAL?

Thank you!

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  • I did not finish reading because after reading 1/2 I looked at the schematic, first I don't see a complete path and second never think a circuit that has a white wire is a neutral, if you can add the complete schematic it would help because what you have provided would never work.
    – Ed Beal
    Commented May 27, 2018 at 5:05
  • What does switch 1 control? What happening with this circuit, and I agree with all of your conclusions, that the middle wire is carrying both hot and switched hot to wherever that wire goes. It may or may not be related to switch 1 but probably is. If this is a ceiling fixture it may have the always hot to accommodate a ceiling fan whether there is one present now or not. If switch one is switching an outlet, is the other half of the outlet switched?
    – Tyson
    Commented May 27, 2018 at 5:21
  • From looking at the diagram one cannot be certain if the power in feed to this electrical switch box is via the left cable black wire or the center cable black wire. In either case the only way to be fully sure is to disconnect all the black wires and then temporarily turn on the breaker to see which black wire is the feed wire with a voltage tester.
    – Michael Karas ♦
    Commented May 27, 2018 at 8:06
  • @Tyson that's good to hear. Both switches control two separate on/off lights in the ceiling as far as I can tell and nothing else... there are no fans anywhere.
    – John
    Commented May 27, 2018 at 12:50
  • @EdBeal that's a complete diagram of what's in this electrical box in the wall, there is nothing more in there. Unfortunately I don't have the other end of the connections, other than knowing that sw1 turns on light1, sw2 turns on light2.
    – John
    Commented May 27, 2018 at 12:58

1 Answer 1

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If you are correct about where power is coming in at (a bit more likely than not, but you'll need to test it or open up the box the middle cable goes to if you want to be sure), then the black wire in the middle cable carries power onward to some other thing that is not switched (like another set of light switches, or some receptacle or outlet somewhere, maybe a smoke detector?). If power is indeed coming in on the black wire in the middle cable (somewhat less likely), then the left cable is going off to another non-switched thing.

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