I'm trying to wire up a living room light on a new switch. Prior owners ran wire from panel to outside lights first then back inside to the electrical box that contains the single pole switch. So I have tried to connect the neutral only to the new switch and tap into the hot wire from my outside switch. Doing this makes the new switch only work when my outside lights are on. Do I need a different switch? or is there anything else I can do?

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  • Can you post a photo of the inside of the switch box in question please? Nov 11 '20 at 2:50
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    You've drawn the wiring to the switch on the right incorrectly. If it really were wired that way it would trip the circuit breaker as soon as you turned the switch on.
    – brhans
    Nov 11 '20 at 3:11
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    It sounds like you have a little bit of experience in electronics or automotive, no idea of the rules for AC mains power, and are just “trying stuff” with the idea of stopping at the first thing that works. Am I correct? Well, don’t do that. Don’t experiment. Lots of things will work and then will kill you. Nov 11 '20 at 5:17
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    Sorry my image is not looking the best. I will try and explain. Panel first to Outside lights,Outside lights run back inside to Switch 1 which full works. On that switch i have ONE hot wire i tested with a non contact volt meter second wire is Neutral since i have NO ground with knob and tube. So what i have done is left neutrals alone i added the inside light Neutral to switch 2 which is the living room. Then since my only power is from Switch 1 i jumped off it is all. Now but switches WORK but switch 1 needs ON for Switch 2 to work.
    – Tom11
    Nov 11 '20 at 17:28
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    @Tom11, please edit your pics directly into your original question so people don't have to wonder whether it's safe to click a link to "ibb.co". I'm not doubting you, but who knows where a link shortener points to...
    – FreeMan
    Nov 12 '20 at 15:48

If your original wiring schematic is correct black and white on the switch this is a switch loop, or switch leg!

the power goes to the fixture. Then the hot comes back to the switch on the white it is not a neutral.

at this point do not connect all whites together as someone said. The white “always hot” should be marked as a hot the black complete’s the circuit to the outside light. The switch turns on and off this connection!

New wiring would need to be run the new light. You cannot tap a switch leg to provide power for another device!

Be careful accepting assistance on the internet because there are a lot of people that don’t have a clue I hope you have not damaged things wiring etc. This is a prime example of internet only electricians in a circle !


Remember that the power comes in through the black wire into the circuit and the neutral returns the power to the source. The switch is just there to interrupt the circuit or complete it. In the illustration, the switch on the left does not complete the circuit; creating a neutral fault.


Step1: Looking at the diagram, connect all the white wires together using a wire-nut.

Step 2: Using a wire-nut and two separate black wires, split your (Black) power wire to connect to each switch (on only one black wire, to one screw, per switch). The black wire that comes from each lamp's circuit will have to be connected to either remaining screws (one wire, to one screw, per switch).

  • This would be correct if the situation where Panel -> Switches -> Lights, but OP has stated it is Panel -> Light 1 -> Switches -> Light 2, and in that setup white is not always neutral. Nov 11 '20 at 19:11
  • Correct glad you understand what i mean. I tried tracing the lines, they go from panel->outside lights which i have two. I took one down and it has white with white black with black but nothing returns back inside, my guess they did the splitting within the outside siding. My only option i guess i could do smart bulbs leaving the switch on constant. or have a electrician just rewire everything for me.
    – Tom11
    Nov 11 '20 at 23:39
  • Wrong! Switch loops commonly are used and the power or hot comes in on the white the switched hot is on the black per code , the white should reidentified as a hot , the white is used as a hot so it can not be confused as a neutral when it is turned off.
    – Ed Beal
    Nov 13 '20 at 14:54

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