The only resolution that Wisconsin has in such a situation is what is referred to as "Partition." When multiple owners of real estate cannot agree, any owner can request that the property be partitioned, or divided up, so such interested party can be in complete control over the parcel they receive. If the property cannot be fairly partitioned, the court orders the property sold and divides up the proceeds.
While I have had to use the threat of a partition action often, most often it brings the parties to the table and results in a resolution of the problem, since neither side wants to see a lot of the equity in the property go into litigation costs.
Good luck!
