I currently have a receptacle/switch combination (the switch controls a light, the receptacle is hot with the switch on or off) with two black wires and one white wired, and ground, coming from the box connected to curren combo switch as follows:

  1. ground wire from box to receptacle ground.
  2. black wire from box to brass screw on one side of receptacle.
  3. white wire from box to brass screw on same side of receptacle.
  4. black wire from box to slver screw (painted black) on other side of receptacle (Other silver screw is also painted black, but is not used).

Note: it is very difficult to determine where the wires come from before entering the box.

The new GFCI receptacle switch combo has 2 back wires coming out of the receptacle case, ground screw, 2 brass screws and 2 silver screws. A piece of tape covers one of the brass screws and one of the silver screws.

How do I replace the old switch/receptacle with the new switch/GFCI receptacle?

  • 1
    Can you upload a picture online somewhere and link to it from here? Commented Feb 23, 2016 at 21:05
  • This answer should help. This answer might also be helpful.
    – Tester101
    Commented Feb 23, 2016 at 21:07
  • Can you include the make and model of the old and new switch? If you don't know the make and model of the old switch, a clear photo of the back of the device should help.
    – Tester101
    Commented Feb 23, 2016 at 21:16
  • Are you sure the white wire mentioned in point C, is not connected to a silver colored screw?
    – Tester101
    Commented Feb 23, 2016 at 21:18

2 Answers 2


This is how a typical receptacle/switch combo is wired.

typical combo switch wiring

A combination GFCI/switch, is going to have a different terminal layout. First, the switch terminals are no longer on the device. Instead they're a couple wires shooting out of the device.

Next you'll notice a set of terminals labeled LINE, with a brass terminal on one side, and a silver on the other. There will be another set of brass/silver terminals, but these will be labeled LOAD (these are typically covered by a sticker).

When wiring the GFCI/switch combo, it will look something like this.

GFCI/switch combo wiring

The challenge you'll face, is determining which black wire is "hot", and which is "switched".


Looking at the back of the receptacle with the ground on the bottom the hot wire black should be on the left and the neutral white should be on the right. Most outlets have different sized openings for hot and neutral the smaller one is the hot. If you look closely the screws are also colored Brass colored is for hot. Silver colored screw is for neutral and the green screw is for ground. The New GFCI’s usually have tape on the “load side” for protecting additional outlets etc. The “line side” is where the incoming power is connected. If you do not have a volt meter or a non contact volt detector it would be a good idea to purchase one. Tester They can be as cheap as ~2$ from china and close to $30 for a fluke. These units light up and or buzz when close to a live circuit. This will be the easiest way to find the incoming hot. The other pair going to the light only the black is switched the whites coming in tied together and the grounds together. If you want the light to be GFCI protected connect the load side brass screw with a piece of black wire to 1 side of the switch and the black wire to the light on the other side of the switch. The white wire to the light will need to be connected to the load side silver screw on the GFCI. I think I covered all the combinations.

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