<prompt> Human: Hello, my fiance just received a check in the mail for a nice amount of money supposedly from the US Treasury, but we have no idea why. It came in a white envelope addressed from U.S. Department of the Treasury Bureau of the Fiscal Service Philadelphia, Pennsylvania. Theres a phone number and USA.gov website. He tried calling, but theyre closed right now. The check itself is addressed to him, from Kansas City, Missouri and says 122013 and Tax Refund. What should he do first? He wasnt even working in 2013, and he said he already received his tax return for 2014.  <response>: Hold off cashing it. Call them. What do you want us to say? 