I'm sorry, OP. Was it a check or did it have a return address? Maybe the person who gets it will send it back or make sure your father gets it back. Or hopefully, your father will realize his mistake and resend it to you. Best of luck to you, OP! Let us know!
It could go two ways: the person mails it back to the return address, or they feel they need it so much they keep it. They could be a starving family and that random $200 could put food on the table for a few weeks. Still, fyl, you need that $200 too damnit!