A director's death, resignation, inability to continue for any cause to act as director or change of residence from the subdistrict in which the director was selected shall vacate that director's office. The board shall by resolution declare the office vacant and a certified copy of the resolution shall be filed immediately by the clerk of the district with the clerk of each municipality included within the district. A successor for the unexpired term shall, within 20 days after the filing of the resolution, be selected by the officer or officers who selected the director whose office has been declared vacant.
Wis. Stat. § 198.09