Tenn. Code Ann. § 8-7-107

A vacancy in the office of district attorney general shall be filled by the voters of the district at the next biennial election more than thirty (30) days after the happening of the vacancy. The election shall be ordered by the governor by issuing proper writs of election to the county election commissions throughout the district, notice being given for one (1) month by publication in one (1) or more newspapers in the district. In the meantime, the governor shall appoint a suitable person to fill the office temporarily until the election takes place.