I'm in the process of replacing a light fixture with a ceiling fan. I replaced the old mount with a pan ceiling support box. The wiring is old (1920s) and inside armored cable coming through the stud. I brought the cable into the box using a duplex clamp and am left with wiring that is too short.

What is the best and safest way to extend this wiring without having to go into the attic replace it completely? I assume I will need to purchase new wire, splice and attach with a wire nut. But which wiring do I buy? And does it matter which wire nut I use?

enter image description here

3 Answers 3


You are sunk

Wire that short can't be spliced or extended. The wire must be able to come out beyond the surface of the box at least 3".

You will need to reroute these cables to a different junction box somewhere the wiring is able reach with the needed spare length inside the box. From there, you can run a /2 w/ground cable to this location, e.g. NM or MC.

The junction box where this happens must have its cover remain accessible without needing tools to disassemble any part of the building. The attic is fine.

  • What is "/2", "NM" and "MC"? My attic's entrance is a hole in a single closet's ceiling. that's another story and problem I need to solve first it seems (old house, 1920s).
    – Kai
    Jan 26, 2019 at 0:04
  • 1
    @kai they are types of cable. /2 designates the number of wires (2 + ground) and NM and MC are types of cable. Given that this stuff is non-trivial to work with, MC (armored cable) particularly, you may want to get some handyperson help for this. Normally I would say "electrician" but if you can visualize what needs doing, they have the mechanical skills, you just need to keep them from illegally shortcutting the job, which most handymen would want to do. (An electrician won't). Jan 26, 2019 at 0:33

I'd use a push-in splice like this one. It should attach to your existing wires and let you attach another piece to bring up up to a better length.

As for size, you can't go wrong with 12 gauge. It will work with 20 amp and smaller.

  • 1
    thanks, I'll give this a try if I can't do it by code first, as suggested in another answer :-o
    – Kai
    Jan 26, 2019 at 0:07

I'd suggest buying a small junction box and installing it so the incoming cable has enough length, splice on new wire, then run the new wire the rest if the way to the current box.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

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