I Had a customer that called and said his fan in his bath needed replaced. After arriving I notice the switche/s were new. He said he replaced all the switches and Rec/in the house. The exhaust fan was on a 3 way switch. He had cross the travler/s.
He did say that he could not understand why once in a while the fan would work.
The bath has a door leading to the back porch. He was smart enought to reinstall a 3 way switch with same. He proably got that advice from a salesperson. Oh course we Know what was happing.
I did however take a look at the rec/ to insure that they were ok.