Tenn. Code Ann. § 2-5-214: Ballot boxes

(a) The county election commission shall furnish for each polling place and for absentee voting at the commission office, locks and standard ballot boxes made of metal or such other material deemed as safe, durable, and secure by the coordinator of elections and the state election commission.

(b) The coordinator of elections shall prescribe the dimensions for such boxes, making allowance for the differences in numbers of voters using paper ballots at the various polling places.

(c) The county election commission shall prescribe and provide the type of lock and seals to be used.