

30A breaker but only 10/2 wire? Help me understand
I am re-plumbing a previously deleted small kitchen. Prior owner had used the galvanized plumbing vent to route wiring to a loft bedroom in the late 1960’s.
The plumbers pulled all the wires and pulled all the breakers out and left them on the ground. Box had a two-space 30 amp, a 20 amp, and three fifteen amps. There are four wires, one of which is 10-2 with a ground. It goes up to old electric baseboard heating. Another goes to an in-roof attic vent fan my parents had put in. (I think some contractor screwed them and added it unnecessarily, as the space probably only needed a loved vent in the eave.
Anyway — I can’t see what use the 30 amp double breaker would be. I thought I’d find a Red/Black/White/Ground wire for it.
Is there a way to use that 30 amp for just a Back/White 120v setup? The front of the subpanel has “Loft Baseboard” written in on spaces 1 and 2. I really wish the plumbers had not pulled all the breakers out so I could use what was written. :/
Any advice would be appreciated. I live out of town and have not had an easy time getting an electrician. The one operation who would come quickly is a large dispatched business and is $$$. I did contract one job with them, for a 220v electric stove outlet and new 50a breaker in the main box. But I don’t want to spend that kind of money on a simple re-connect