Tenn. Code Ann. § 17-1-105

No judge or chancellor shall practice law, or perform any of the functions of attorney or counsel, in any of the courts of this state, except in cases in which the judge or chancellor may have been employed as counsel previous to the judge's or chancellor's election. A newly elected or appointed judge or chancellor can practice law only in an effort to wind up the judge or chancellor's practice, ceasing to practice as soon as reasonably possible and in no event longer than one hundred eighty (180) days after assuming office.