This has already happened in Arizona.
Authorities have made an arrest have a number of ballots were damaged when a United States Post Office collection mailbox was lit on fire in Phoenix, police said.
An individual lit a fire inside a drive-up collection mailbox at a USPS station early Thursday morning, according to the Phoenix Police Department, which said it responded to the scene at 1:20 a.m.
The Phoenix Fire Department was able to open the mailbox and extinguish the fire and the Postal Inspector took possession of the damaged ballots and miscellaneous mail, police said.
Phoenix police initially said that approximately 20 electoral ballots were damaged, though the Arizona Secretary of State's Office later said it believes the fire only destroyed five ballots while warning that the final figure could still change.