SCAM
Supposedly, the guy's name was Sergeant Michael Ferguson , of the United States Customs and Border Protection...
He proceeds to read me seven pages worth of notes real fast (ever talk to a federal agent who reads a script? me neither) saying there was "package" that is a check for $450k and, after a lot of rigamaroll, it comes out that you have to Western Union money to Costa Rica. Yeah, right.

I got this phone call from this man saying that he works for the government. That they keep tabs on this certain sweepstakes to make sure that they are giving people a fair chance to win. The man sounded like he was in an empty warehouse.

Yes I got a call from this number as well. Some woman called saying I won some kind of money.

This caller introduced himself as from the Federal Trade Commission (I forget his name) and asked if I had any phone calls from people mentioning sweepstakes winnings. I happened to have had those calls lately. This number could be legit, or a check to see if I could be duped. I don't trust anyone who makes unsolicited phone calls. I could try to verify it with the FTC.