There was an older gentleman sitting on the front steps (outside the security gate) of the Blaine House next to the sidewalk with a sign that read 'F U Janet Mills'.
As it actually turns out, you should leave it there. Yep, if you go to check your mail and you find a dryer sheet inside the mailbox you should seriously just leave it there. Unless you have a really strange neighbor playing a super-odd prank on you, the sheet was most-likely left there by your local mail carrier...