You need property owners permission to place signs on their property even if it is on the NH DOT or Utility company right of way. There a number of instances where copious numbers of signs have been placed in areas where they were not welcomed.
It is illegal to place campaign literature that doesn't have a paid postage on it in some one's mailbox or even touching some one's mailbox. The United States Post Office is allowed to fine you. The fine can be anywhere from $100 to a maximum of $5,000, and you may even get an extra bill in the mail from the post office, for due postage.
The BoS have a policy implemented a number of years ago due to safety concerns to not allow any political campaigning at the Transfer Station.