Mysterious gift

I just got home from a house-warming cum mambo party and found this in my mailbox:

8 easter chocolate eggs in a lacy blue bag with X X written in red ink on 2 corners of it. ??!!!??? I peered into the other mail boxes and did not see any similar bag inside ( i thought it might be a Happy Easter gift for everyone in the apartment hah). Ok so who left it there??????? I don't like mysteries :( and I don't think i'll eat the chocs since they are from a suspicious source. What a waste :(