I wanted to install a timer light switch but when I opened the switch I noticed there were only two wires and a ground and both wires were the same color. The timer switch has a white black and blue wire with no place for the ground. Is it possible to replace this switch with the timer switch?

  • Yes, but not with the timer that you have. You need timer like the intermatic SS7C that uses two wires.
    – Tyson
    Jul 3 '16 at 1:10
  • 1
    Can you post a photo please? Something doesn't add up here -- it sounds like the white wire you're after is in the back of the box, or you have conduit as Harper mentioned which'd make adding a neutral a relatively simple job. Jul 3 '16 at 3:02

Sounds like you need a neutral wire for that timer switch to work. It's simple logic really: the timer has to get power to run the timing mechanism whether the lamp is on or off. There are clever ways to steal power when the lamp is off, but not when it's on. So it needs a hot (which will be one of those wires) and a neutral.

Both wires being the same color is a hopeful surprise. Same-color NM is hard to find, so good chance your wires are single-wire THHN/THWN in conduit, and the electrician ran two blacks (or whichever color he used) because it is a correct color for both always-hot and switched-hot. You may be able to pull a neutral wire (white) by fishing.

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