Wiring – Changing out an old light switch


Some background on this: the house is old, 1960's, and the previous owners loved having multiple switches run a single light.

I am changing out a light switch inside the house that runs an outside light and this light has two switches, one in the garage and one in the dining room. Yeah very odd spot.

The new switches I see have 3 screws on them, 1 for the hot wire and two for travelers. But the old switch has 2 white wires coming in and 2 black wires. One black wire is hot and one white wire is hot. How on earth do I wire the new switch?

In the pics below I tapped the hot wires.
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and second pic
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Best Answer

Assuming the rocker on this switch doesn't say ON and OFF, this is most likely the middle switch in a "4-way" arrangement. This is when three or more switches control a light. The switches on the "end" of this setup will be the three-way switches you are used to. The one(s) in the middle will be 4 way switches with 4 screws. Rather than connecting travelers to a common screw like a 3-way, they flip the connections of the two travelers, so there are two travelers in and two out.

You might say that there are only two switches controlling the light, and in that case one of the three ways on the end could have been removed over the years. You could try and diagnose that and figure out what all the wires do, but the simplest thing would be to get a new 4-way switch and use that.