Wis. Stat. § 234.44
Notwithstanding any provision of this chapter or any other law, in the absence of fraud, all obligations issued prior to May 4, 1976 purportedly pursuant to this chapter, and all proceedings prior to such time taken purportedly pursuant to this chapter for the authorization and issuance of such obligations or of obligations not yet issued, and the sale, execution and delivery of such obligations issued prior to May 4, 1976, are hereby validated, ratified, approved and confirmed, notwithstanding any lack of power, however patent, other than constitutional, of the issuing authority or the governing body or officer thereof, to authorize such obligations, or to sell, execute, deliver the same, and notwithstanding any defects or irregularities, however patent, other than constitutional, in such proceeding or in such sale, execution or delivery of such obligations. All such obligations issued prior to May 4, 1976 are binding, legal obligations in accordance with their terms.
Wis. Stat. § 234.44