Wis. Stat. § 843.10: Counterclaim that plaintiff be required to sell land to defendant.

In an action in which the plaintiff demands the relief specified in s. 843.09, and in which the defendant makes the allegations specified in that section and in addition alleges that the building is partly on plaintiff’s land and partly on land in which the plaintiff has no interest and that the portion of the building built or encroaching on plaintiff’s land cannot be removed or separated from the remaining portion without serious injury to both parts, the defendant may demand judgment that the plaintiff be required to sell the defendant the land on which such building stands or encroaches, together with such additional land as may be necessary or equitable in the circumstances.