I want to add a canless ceiling fixture (pink in the photo) to a closet, connect it via the existing fixture (purple line in the photo) and operate on/off on the existing switch.

enter image description here

From the attic I believe the ceiling light in the picture is the end of the line.

enter image description here

Is this correct?

  1. cut canless hole
  2. wire canless and pass romex under joist to existing fixture
  3. wire blk-to-blk, wht-to-wht, as shown in diagram

enter image description here

  • 2
    The outside of that cable, just outside the box, looks rather burnt. Check on that to see if it's actually a scorch mark, indicating that there are serious electrical issues, or if it's just some sort of dirt that's rubbed off on the cable housing. There's another scorch mark and what looks like smoke damaged insulation at the bottom edge of the picture, too. Consider taking down the existing light and opening that box to look at the individual wires to see if they look burnt. If so, you've got to address that issue first.
    – FreeMan
    Jan 17, 2022 at 14:07

1 Answer 1


I believe the steps you listed are correct, with the exception of "pass romex under joist to existing fixture". The cable should be stapled to the sides of the joists when it runs along them, and drilled through the joists at a 90 degree angle when it runs across them.

See this answer for more detail: What is the proper way to run wires along/across basement ceiling joists?. It's about a basement, but the same idea applies, I believe.

EDIT: Also, make sure your canless fixture is "IC rated", meaning it is allowed to contact insulation.

FOLLOW-UP EDIT: Make sure you have enough circuit capacity to add another fixture. Most canless LED fixtures are pretty low-wattage, but you should turn off the breaker for the existing light and see what else goes off along with it.

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.