I'm planning to add a set of recessed lights to an existing circuit in my home. The existing circuit is fairly simple: one light, controlled by one switch, and there is no insulation in the wall or ceiling.

My dilemma is in adding the fixtures into the circuit between the existing fixture and the switch. I will need to splice additional wire into the circuit, but I'm certain there isn't enough slack to draw the existing line into the fixture's junction box to make the connections.

Should I run new line from the existing fixture to ensure that the connections happen inside the box? Otherwise, can I splice a short segment into the existing line to get the slack I need?

  • 1
    Good question. It's not an exact duplicate, but the answer he needs is available at @NiallC. link. Commented Sep 24, 2013 at 17:21
  • 2
    Retracting my close vote. I think this should stay merely because the title is so perfectly searchable. Commented Sep 24, 2013 at 17:42

2 Answers 2


It is generally not acceptable to have wire junctions be inaccessible. The rule of thumb is: All junctions must be in a box, but that box must be accessible - you cannot legally close a box up behind drywall.

There are some limited exceptions, as noted here.

You should run a new line if you don't have the slack.


Short answer: NO.

Long answer: All splices must be in a junction box, and the junction box must be accessible.

Caveat: There are some products that can be used to splice behind drywall outside of a box. See this answer here: https://diy.stackexchange.com/a/4535/928

But, I think it's preferable to fish a new line.

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