Wis. Stat. § 323.53

(1) EMERGENCY INTERIM SUCCESSORS TO OFFICE OF GOVERNOR. If, during a state of emergency resulting from enemy action, the governor is unavailable and the lieutenant governor and the secretary of state are unavailable, the attorney general, state treasurer, speaker of the assembly, and the president of the senate shall in the order named if the preceding named officers are unavailable, exercise the powers and discharge the duties of the office of governor until a new governor is elected and qualified, or until a preceding named officer becomes available; but no interim successor to those offices may serve as governor.