I'm doing some renovating and where I want to put a closet I'd like to put a light. There is a junction box there which appears to have been used as a light before and would be ideal. It has only 1 3-wire coming in and 1 out, twisted together. They moved the light elsewhere. I'm hoping I can use this box for a light with its own switch and somehow get power from it.

So the current configuration goes like this:

Switch 1
 J-box (old light box?)
Switch 2
Switch 3 (power)

2-wire from the light to the first switch. 3-wire from that switch to the junction box and 3-wire to 2 other switches. Power comes in at Switch 3. Can I get power from this box or do I have to use a new line?

  • @isherwood I've edited to show power comes from the last switch, Switch 3. It appears that there are 3 outlets and two other lights on the same circuit. – fullerm Nov 19 '17 at 2:02
  • What do those switches control? Can any of the three turn the light on or off? -- Also, look at the switches and the connections in the boxes. It looks like switch 2 is a "four-way", ie. it has four terminals (besides the ground). – A. I. Breveleri Nov 19 '17 at 2:23
  • @A.I.Breveleri Each switch can turn light on/off. Yes Switch 2 is a "four-way". Switch 1 and Switch 3 are "three-way". – fullerm Nov 19 '17 at 2:29

You do not have enough conductors in those cables to add a constantly powered device at the j-box. You would have to either run another wire from switch 1 to the j-box, or abandon the use of switches 2 and 3 and control the existing light with switch 1 only.


The day is saved by smart switches.

In this case, you reconfigure the circuit for an appropriate smart switch. Locate a "master" smart switch at switch 1, and smart switch remotes in 2 and 3. The 3 wires (besides ground) become

  • neutral (white)
  • always-hot (black?)
  • communications line (red?)

The cable to the lamp is switched-hot and neutral, of course.

Now you can tap always-hot and neutral for a lamp, and either have a pull cord at the lamp, or branch off a new switch loop. Remember switch loops must now be wired in /3 cable and provide a neutral.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.