Wis. Stat. § 889.10

When a public officer is required or authorized by law to make a certificate or affidavit touching an act performed by the officer or to a fact ascertained by the officer in the course of the officer’s official duty and to file or deposit it in a public office such certificate or affidavit when so filed or deposited shall be received as presumptive evidence of the facts therein stated unless its effect is declared by some special provision of law.