Wis. Stat. § 75.10
Whenever, by mistake or otherwise, such treasurer neglects or fails to include in the treasurer's published list any such tract or tracts of land or to publish such list in accordance with the requirements of law, the same may be published at any time within 2 years after the expiration of the period of redemption. Such publication shall be made in the same manner and for the same time as prescribed in the preceding sections, and such treasurer shall specify in the treasurer's notice accompanying such published list when the time for making redemption of such lands from such sale will expire, which time shall not be less than 6 nor more than 10 months from the expiration of the full 2 weeks required for the aforesaid publication. All tax deeds made upon such tracts of land after the expiration of the regular period of redemption shall, after the expiration of such extended period of redemption, be as valid and effectual as if such publication had been made at the time required in such section.
Wis. Stat. § 75.10