California house built around 1983. I have just replaced an old incandescent porch light fixture with an integrated LED sconce, working fine on the existing on/off light switch.

Now I want to replace the on/off light switch with a countdown timer. But I'm not sure if I can, with the wiring I have?

The existing on/off switch just has two black wires on it, one connected to the top right screw and one on the bottom right screw. The wires in the box are as follows:

Two white-covered groups of three wires - a bare copper, a black, and a white - are in each group. The two white wires are twisted together and capped at the rear of the box. The two bare wires are pushed together at the rear of the box and are touching but not capped.

Lastly, one black wire is attached to the top right screw, the other black wire is on the bottom right screw, of the existing light switch. So just those two wires on the switch.

Can I replace the existing on/off switch with a countdown timer? I should look for one that says compatible with LED, is there anything else I should look for? One that requires neutral, or one that only requires ground no neutral? Is this even doable? I am just a homeowner that has replaced a few fixtures and receptacles one-for-one, never changed any wiring around before. Thank you for any help or info.

1 Answer 1


You should be fine

What you are describing is classical "power to the switch" wiring where hot (line/live), switched (load), and neutral are all available at the switch box. So, you will have no trouble using any "neutral required" timer there as long as you follow the instructions.

For your specific timer (the Defiant one), you'll need lengths of white and bare or green wire to cap in with the existing white and bare, respectively, wires as pigtails (12AWG THHN always works for an insulated pigtail wire).

  • 1
    I am truly n00b here... What is recommended wiring? Do I use a length of white wire for my neutral and cap the free end together with the other two white wires? And do the same with a bare wire for ground - cap the three together?
    – Kat
    Oct 17, 2023 at 0:38
  • @Kat -- the instructions for your timer switch of choice will specify what to do Oct 17, 2023 at 0:38
  • @Kat Be sure to turn off the power at the breaker since one of the wires going to the switch will be hot.
    – JACK
    Oct 17, 2023 at 0:50
  • @jack Thanks, yes, I always do.
    – Kat
    Oct 17, 2023 at 0:55
  • 2
    @Kat -- your idea as to using a length of white wire (12AWG THHN always works) capped together with the existing white wires is the correct one, likewise with a bare wire for the grounding wire. Oct 17, 2023 at 2:18

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