Cute idea! I also like the idea of having "Merry Christmas" on the backside and just flipping to go from Halloween to Christmas decor in a jiffy, cuz let's be honest - the Halloween decor stays until at least December! ;)
UPDATE: Goggle Eye Card Made this using a picture frame I picked up at Target, on clearance for $1.78! Found a combo sized pack of googly eyes at Dollar Tree. Painted the frame black first, to cover up the design underneath then glued eyes on using craft glue. Fun, cute and inexpensive!