I had a guy in who I discovered was NOT an electrician. He rewired my outlets (among other things). My upstairs outlets are wired on circuit 5, until the second to last outlet–and until that outlet they all work. That one does not have the trim on it. It is fed by #5, but then on the other side is fed by #17. #17 feeds an outlet that reads not grounded, and then feeds this one.
What did he do, and what do I do at this point?