# Replacing self contained switch with 3 wire sets?



## dflux (Feb 18, 2014)

Replacing the above switch in a mobile home.  Was not expecting to see 3 wire sets like this.  My grandfather was looking at it saying he's never seen these before.  Wondering if it was a different type of switch.  We are replacing all of the outlets and switches in the house.  So simple question just to assure the old man...

Just group the two sets as one together as they are already and wire this just like we would any other light switch right?  It ticked him off not ever seeing that before.  So I told him I would ask to be sure.  lol


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## nealtw (Feb 19, 2014)

It looks like you have power coming in and then going out to another outletor switch and power going thru this switch to a light. Or you could power coming and the switch feeding two lights. Are changing the box out too or just replacing what you have with same?


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## CallMeVilla (Feb 19, 2014)

YEP ... mobile home hardware all right ...  Here is a silent video on how to replace.

[ame]http://www.youtube.com/watch?v=KNfCug586aQ[/ame]

If you have three wires, you might be looking at a 3-way switch which can turn a light on and off from two different switch location.  

Be careful and replace wire for wire ...


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## dflux (Feb 19, 2014)

"It looks like you have power coming in and then going out to another outletor switch and power going thru this switch to a light."

I do believe you are right.

"changing the box"

Yes


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## nealtw (Feb 19, 2014)

So you will need wire nuts and pigtails. Pigtails are just short peices of black and white wires to make the conection.
You will have to figure out which wire is going to the light. The black from the light cable goes to the switch. All three whites are nutted together. The other two blacks are nutted together with a pigtail (black). The other end of the pigtail goes to the switch. Don't forget the grounds to the screw at back of box and switch.


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## JoeD (Feb 19, 2014)

> You will have to figure out which wire is going to the light.


Nothing to figure out. Take the bottom two blacks and connect with pigtail to one screw of new switch. Take top black and connect to other screw. Connect all three whites together.


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## funkyvailchick (Jan 19, 2020)

I just ran into the same thing as I am replacing a switch. I am replacing the box and putting in a 3 way switch. I jut read this solution which my electrician confirmed was ok to do.  Just curious though, why didn’t you recommend testing the wire to isolate the hot one.   I tested the “black” wires, to find the hot one.  Upon a closer look there are 2 gray wires and one black wire.    I’m pigtailing because it’s literally impossible to get 3 12 gauge wires under the screw.  If the wires aren’t properly secured the fixture will fail.


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## Jeff Handy (Jan 20, 2020)

Putting more than one wire under a screw is dangerous, against code, and lazy. 
And can lead to arcing. 

I have found this condition in receptacles, switches, and even breakers. 

In breakers, I hear it referred to as a “double tap”.


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