Wisconsin Statutes Fences (Ch. 90) § 90.06. Relocation of fence

(1) When any owner or occupant of land builds a fence before a boundary line has been located between that land and any adjoining land and the location of the boundary line establishes that the fence is located on the adjoining land, the person who built the fence or that person's grantee, devisee or heirs shall be the owner of the fence. The owner of the fence shall relocate the fence to the boundary line within 30 days after service of written notice of the location of the fence upon the owner of the fence by the owner or occupant of the land upon which the fence is located.

(2) The notice under sub. (1) shall be served personally on the fence owner or by leaving a copy of the notice at the fence owner's usual place of abode with some member of the fence owner's family who is of suitable age and discretion. If the notice is left with a family member, the family member shall be informed of the contents of the notice.

(3) If the relocation of the fence is not made within 30 days after service of the notice under sub. (2), the party who served or caused the notice to be served may relocate the fence to the boundary line and recover the expense of doing so from the fence owner. However, no fence that is subject to relocation under this section shall be relocated by the party giving the notice during a time when annual crops will be damaged unless the owners or occupants of the adjoining lands mutually agree.