Art. 806.  Public officer

When an officer of the state, or of a municipality, parish, political subdivision, agency, or public corporation, who is a party dies, resigns, or otherwise ceases to hold office, his successor may be substituted therefor on ex parte written motion of the successor or any other party, supported by an affidavit of the truth of the facts alleged.  A copy of the order substituting the successor shall be served on the adverse party by mail.