I received an envelope from "PO BOX 140" today., and it is addressed to some woman who hasn't lived at my address in ages. I've never met her and I'm sure I wouldn't want to meet her anyway. So I did what I do with all mail I get which belongs to someone else, and that is I write "DECEASED - RETURN TO SENDER" on the front of it and pop it back in the mailbox. This really messes them up at the other end so they just close the account, end of.