I'm rewiring part of my house to get rid of knob and tube. I found a weird situation:

  • A light socket in a stairwell has two wires: incoming hot and outgoing hot to upper switch.
  • Upper switch has 3 wires: incoming hot from light, outgoing two travelers.
  • Lower switch has 3 wires: 2 incoming travelers from upper switch, 1 outgoing neutral.

The neutral is spliced in some random joist bay and is the last remaining active piece of a big section of wiring that I'm otherwise ready to get rid of. This lower switch is 25 ft away from the bottom of the stairs, for some reason.

If I were to prune back these travelers and neutral, could I run them to a new switch closer to the base of the stairs? I know that new knob and tube is not allowed. I would do all splicing inside of boxes, and new wiring would be all romex. But the travelers and neutral would be coming into this box from separate locations, as is currently the case.

Is that code compliant? Is it safe?

My alternative is to tap into a nearby box and run all new romex, leaving only the incoming hot at the light fixture, capped off. I'm sure this is better, but is it necessary? It's a lot more work.

  • 2
    I’m sure folks will weigh in on code, but my opinion: bite the bullet. It’ll feel good to have the old wire gone, and when you sell the house, that disclosure won’t nag at you. Mar 13, 2023 at 0:37
  • 1
    Switching a lamp on the neutral side (as yours is currently) is not, and was never code-compliant, no matter what the wiring method used.
    – kreemoweet
    Mar 13, 2023 at 16:40

1 Answer 1


You're not going to rewire it like that, with current flowing in a big loop. You're going to do one of two things:

Deliver always-hot+neutral to the first switch, then /3 cable to the second switch, then /2 cable to the lamp.


Deliver always-hot+neutral to the lamp, then /3 cable to the first switch, then more /3 cable to the other switch.

Replacing K&T doesn't get you out of 404.2 (neutral to first switch)... it certainly doesn't get you out of 300.3. (No loops). Mind you, many of the K&T installations of the day were originally used with DC power, where loops don't matter.


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