Electrical – 220 outlet with no ground

With a 14/3 (white-black-red-ground) and 14/2 (white-black-ground) coming into this box, CoAstroGeek suspected that this might be a switched outlet. Exactly right.

There is a switch in the room next door that we had no idea what it was for. once i switched it on, there was power to the outlet. the short of it is- the room used to be the garage and was converted into an office 40 years ago. there are two switches on the wall in the room next door; one for an exterior light and one for that outlet. must have been an overhead light or something.

There are multiple combinations possible.

From what you have said so far here is what I am thinking:

Cable A or B is the hot feed from the main panel. The other cable, either A or B is the feed to the other receptacle. Cable C is the feed to the switches and the red wire is the switched hot wire returning from one of the switches.

It sounds like at least one receptacle in the room was switched for a floor lamp. It doesn't have to be split wired both plugs on the receptacle could be switched.

It could be the receptacle in your drawing or the other or both. The switched hot should be the red wire. If you connect the red wire to a receptacle you should not connect a black wire. Unless you are going to remove the connecting tab on the hot side of the receptacle and split wire the receptacle.

You should take some voltage readings to determine which cable is the hot feed from the panel. Then, with the circuit shut off, you can use the resistance or continuity setting of the meter to determine which cable goes where and which wire is which.

Good luck!