Well, it seems that the State of Wisconsin has gone from one extreme to another in the area of codifying conditional use permit (CUP) law. Where before there was nothing, last fall the Wisconsin State Legislature adopted amendments to county, city, town and village land use statutes that set out standards to guide and limit discretion of local zoning bodies in granting and denying CUPs. The legislation was a direct outgrowth of a very unsatisfying Wisconsin Supreme Court decision (AllEnergy Corp. v. Trempealeau County), where it took 88 pages and three separate opinions for the court to uphold a CUP denial by a county board of supervisors; the CUP was sought to carry out a frac sanding mining and processing operation.
The new Wisconsin law codifies matters pertaining to CUPs that are largely recognized in Minnesota, but only in various court decisions and not in state statute. Here is a link to a recent article I wrote summarizing the new Wisconsin law on CUPs.