'Selling The OC' Alex Hall Says She Wouldn't Be Diddy's Realtor

"Selling The OC" star Alex Hall says she wouldn't sell Diddy a home in Orange County, California if he came calling after prison ... even if his budget was $30 million.

Alex was our guest host Friday on "TMZ on TV" and we asked her straight up if she would work for Diddy as a realtor when he's done serving his sentence in New Jersey.

Diddy's twin daughters are hobnobbing with Hollywood celebs, which has us wondering how Diddy will be received when he's out of the pen ... and it sounds like there will be a mixed bag.

Alex says she wouldn't sign on to be Diddy's realtor, but she does tell us how she would be able to squeeze some money out of the deal without touching it with a 10-foot pole.