I take it out, open it, and inside are a pair of slip-on sneakers from the United Colors of Benetton. Not exactly a brand I shop.
I take the shoes out of the box. It still has a pricetag on it - apparantely marked down to $40. I compare them to the shoes I am wearing currently. Same size. I try the shoe on, it fits.
I never bought these shoes, and I have absolutely no clue where they came from, or how they got into my office.