Wis. Stat. § 856.16: Self-proved will.

(1) Unless there is proof of fraud or forgery in connection with the affidavit, if a will includes an affidavit in substantially the form under s. 853.04 (1) or (2), all of the following apply:

(a) The will is conclusively presumed to have been executed in compliance with s. 853.03.

(b) Other requirements related to the valid execution of the will are rebuttably presumed.

(c) A signature affixed to the affidavit is considered a signature affixed to the will, if necessary to prove the due execution of the will.

(2) Admission of a will under s. 856.13 or 856.15 is not dependent on the existence of a valid affidavit under s. 853.04.