I wanted to put an air conditioner in my garage. Thinking I would need 220 for this, that is exactly what the electrician did along with some other work we were having done at the time. I just bought the right air conditioner window unit for the size space I have to cool and it runs on 110, not 220. How do I make this outlet 110 instead of 220 like it was wired for?

To do it correctly you should change the breaker to a single pole ,the breaker and wire should be sized to the specifications on the data tag on the A/C, Keep in mind that a 110 volt air conditioning unit of the same tonage will require twice the amp draw of a 220 volt unit ,so the wire size needs to be looked at. If both wires are colored , you should buy some white tape and tape one wire to look white (both ends of the same wire) to designate this wire as the neutral wire and connect it to the neutral bar in the breaker panel. Purchase a receptacle that matches the plug on the A/C.