I was contacted by this person to purchase a TV I had put up for sale on Craigslist. They will falsely claim that money has been forwarded to your PayPal account but that it is being held by PayPal until a shipping deposit or some other nonsense charge has been paid by Western Union to a US address. It comes complete with false PayPal emails, false email addresses etc.
It doesn't make any sense to forward money that you haven't received, but I guess it has worked in the past or they wouldn't still be trying it.
So be warned!