Wis. Stat. § 24.37: Ejectment.

If any person holds or continues in possession of any public lands without written permission from the board, or contrary to the conditions or covenants of any lease or written agreement, or after the lands have been forfeited to the state, that person shall be liable to an action by the state or any purchaser from the state for an unlawful detainer or other proper action to recover possession of the lands and for damages for the detention of the lands.