My old light switch did not have the common labeled and just had two brass screw connectors. Coming in the bottom of the box was a black, a white, and ground wire. The ground was connected to another ground and out the top not connected to the switch. The black was to the switch and the white to another white and put the top. Coming off the switch was a red that went out the top. Not sure which to connect to the common connector and which to the other. I also wrapped the ground wire around the ground screw.
Here is how I wired the new switch:
Coming into the bottom of the box was a black, a white, and ground. The ground was wired to another ground coming in from the top of the box, the old switch was not grounded. The white coming in the bottom was connected to another white from the top (I assume straight to the light) the black was looped around one terminal and then connected to a black coming from the top of the box. Then there was a red wire coming from the top of the box on the second terminal on the switch.
This should be a better picture (sorry I’m on my phone and first time posting here). I went and got a single pole switch. Can o wrap the ground wire around the ground screw then up to the ground wire coming in the top?