eBay

I have two listings without "Best Offer" set. I received a message from a buyer offering to by both for a price I think is fair. Can I accept this?

I received a "Baseball Card" in the mail via USPS with tracking number. It had a return address for the sender but I haven't found him on ebay. It was not any baseball card I purchased on ebay so I suspect someone sent me the wrong item. Any idea how...

What are my options to resolve the issue of a mistaken bid?