If after the expiration of 15 months from the time of the sale of any real estate upon execution any part of the premises sold shall remain unredeemed, the sheriff of the county in which the real estate is situated shall, on demand, execute a deed for the unredeemed premises to the person entitled to the deed. The deed shall convey all of the right, title and interest which was sold upon the execution, except that no deed shall be issued after 20 years from the date of the sale.
Wis. Stat. § 815.55