Wis. Stat. § 75.19
A county holding a tax certificate, instead of taking a tax deed, may foreclose the certificate by action as in a case of a mortgage on real estate at any time after 2 years from the date of the certificate, except that when costs incurred by any city or village for razing, removing and restoration of the site to a dust-free and erosion-free condition are included in the amount due for taxes, the period of redemption shall be one year from the date of the certificate. The county may, in any case involving the right of redemption or interest of any minor or person adjudged mentally incompetent, after a tax deed has been issued under this chapter, foreclose the right of redemption or interest of the minor or person adjudged mentally incompetent. In such an action the minor or person adjudged mentally incompetent must appear by guardian ad litem, and the general guardian, if the person has one, shall be joined as a party defendant. All the laws and rules of practice relating to the foreclosure of mortgages, as to the persons necessary and proper to be made parties, pleading, evidence, the judgment of foreclosure and sale, the right of the county to be subrogated to the benefits of all liens upon the premises necessarily satisfied by the county in order to save the lien of the certificate, the right of the defendants or any of them to redeem the premises at any time before sale and costs and disbursements, including the necessary expenses for an abstract of title, shall, so far as they are applicable, prevail in such actions. When costs are allowed to the county, the costs, exclusive of disbursements, shall be discretionary with the court but shall not exceed the amount of the certificates at issue in the action, and the costs when allowed shall be an additional lien upon the property described in the certificates. The defendant may, in all cases within the time limited by law for answering the complaint, execute and deliver to the county a quitclaim deed of the lands described in the complaint, conveying all the right, title and interest of the defendant at the time of the commencement of the suit or may, within such time, either after having delivered the deed or without delivery, answer disclaiming any title to the lands in question at the time of the commencement of the suit, in either of which cases the county shall not recover costs against any defendant who quitclaims or who shall establish the disclaimer at the trial. The sale in such actions shall be conducted, certificates made and filed, the report made and confirmed and a deed executed and delivered in the same manner and with the same effect as in actions for foreclosure of mortgages.
Wis. Stat. § 75.19