I have a dimmer switch, and want to install a regular switch so can use a ceiling fan (which I installed). When trying to change the switches, I'm confused (see picture). Out of the (old) dimmer switch is a green ground wire, and next to it a black wire (which is neutral; the switch next to it has only two black wires, one being neutral). The red wire from the switch to upper right is not used, and labeled for use with a three-way switch, which this is not. Out of the wall is a red and another black, which were twisted together with the other red from the dimmer. So.....for the regular switch, do I use the black out of the wall only, or both black and red (of note, I capped the red in the ceiling box, and only used the black, white and ground to wire the fan to the ceiling). What do I do?

 

The black and the red go to one terminal on the switch.
The single black goes to the other terminal on the switch.