May 22, 2012
Based on your post, I would guess that you have a golden opportunity to stick it to a scammer.
Contact the Postal Inspectors. Make sure you explain that they used your mailbox in posting the message, and that this appears to be a scam activity.
You can reach the Postal Inspectors through your local post office, or you can file a complaint through their web site. Since this is a local event, I suggest going through your post office for a more immediate response.
Hang on to the sticky note!
Good Luck.