Right now I'm working out of a detached two car garage. On the breaker box it has a slot that's labeled washer + dryer/garage and its 30 amp 110/220v breaker. Flipping this cuts all power to the garage, as expected. When I look at the wires in the basement I've got a 12/2 and 14/2 (labeled as such on the wire casing) headed in the direction of the garage, but when I open up the first switch out there it has two sets of red, white, black, and bare copper wire out there. I thought the nomenclature of xx/2 meant two insulated with one bare, but I could easily be wrong. Is this set up even likely? Why would there be two different gauge wires for the same amperage breaker? The reason I am even delving into all of this is because I want to get a 220v outlet out there and was looking at possibilities. Would this be very easy/at all possible on the current wiring? I hope I explained well enough for others to understand, but I can get more info/pictures/anything else if need be. Thanks!
Edit, if it helps, I could also mention that the house and garage were built ~1952 and as far as I know has had no updating done with the electrical.