The Wisconsin FA-4121V Affidavit of Mailing is an official document used to prove that mail was sent to a particular recipient. It is typically used for legal notices, court papers, and other documents that require proof of service. The affidavit is usually filled out and signed by the sender and a witness, and it must include the date, time, and method of mailing used. There are two types of Wisconsin FA-4121V Affidavit of Mailing: the Long Form and the Short Form. The Long Form requires more information, including the sender's name, address, and contact information, as well as the name and address of the recipient. The Short Form is similar but does not require as much information.