Tennessee Code Title 58. Military Affairs, Emergencies and Civil Defense § 58-1-205

(a) Members and units of the national guard shall assemble for such drill, or other equivalent training, instruction or duties during each year and shall participate in such field training, encampments, maneuvers, schools, conferences, or other similar duties each year as may be ordered by competent authority; provided, that no assembly of any unit of the national guard shall be ordered in time of peace for any day during which a state or federal election shall be held, except in case of disaster, riot, attack, invasion or insurrection or imminent danger thereof.

(b) Members of the national guard, with their consent, may be ordered by the governor, or under the governor's authority, to perform special duty, including, but not limited to, duty, as a member of, or in any other capacity with, any military board, or as an investigating officer or medical examiner.