Hello,
I am helping my brother clean up and run a couple of new legs in his house, and I have encountered an interesting twist. The home runs are all 12/2 wire, but after the first connection, it usually will drop down to 14/2. All of the breakers are 20 amp in the sub panels. This house has clearly been this way since it was built in the late 80's. I thought the breaker could be no larger than the smallest wire in the chain. What's up? Thanks in advance
Kendal

You are correct, should be on a 15 Amp Breaker.

You are correct, should be on a 15 Amp Breaker.

Looks like someone pulled a fast one on the electrical inspector!

I'm a commercial electrician, and don't do too much Romex work, but the last house I wired the 14-2 Romec had a blue jacket, the 12-2 was yellow, and the 10 was red.

If 14-2 is used for travellers, that circuit will be limited by a 15 Amp Breaker.