My house has a hallway with a light and light switch. The switch controls electricity to the light correctly but also electricity to both the entire adjacent rooms (office and front from). When the switch is off both rooms get electricity but when its on they don't. We've always left the switch in the off position and not used the light but I'd like to fix it.

I'm guessing two of the wires should be pigtailed to bypass the light switch entirely? There are three black wires and a ground going to the switch. I've made two diagrams below of the state of each terminal in both the on/off position. Thanks for any help.

switch on

switch off

left side

right side

  • Does the switch have four separate screws on it with four wires connected? – ArchonOSX Sep 24 '17 at 18:41
  • did it work this way since you first used it, or has any changes been made to anything electrically since you first used it? Did it ever work differently before? Where do you live (country)? – noybman Sep 24 '17 at 18:49
  • Are the screws color coded or otherwise marked? – bib Sep 24 '17 at 19:31
  • It's a 3-way switch. On this particular switch, and possibly none other extant, the black/common screw is in the upper left. – Harper - Reinstate Monica Sep 24 '17 at 22:03
  • Yes, four separate screws with four wires. Left top is black and Left bottom is gold. Right top is green ground and Right bottom is black. The switch has been wired like this since I moved in. – Dan Cohaan Sep 24 '17 at 22:28

And this is why people shouldn't slap wires on screws willy-nilly

The previous installer apparently thought that all wires belong on screw terminals, which isn't true here, and combined with the 3-way to yield the bizarroland behavior you see here. Fortunately, this is easy to fix.

Make sure the breaker's off. Take the two wires off the left hand side of the switch and wire-nut them to a short length of the same size wire to serve as a pigtail. Land this pigtail on the black screw on the switch. Turn the breaker on, and enjoy your outlets working all the time now.

  • Thanks @ThreePhaseEel. I made your suggested change and everything is working correctly now. – Dan Cohaan Oct 8 '17 at 14:25

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