Wis. Stat. § 140.18: Stamping device.

(1)

(a) A notary public is responsible for the security of the notary public’s stamping device and may not allow another individual to use the device to perform a notarial act.

(b) On resignation from, or the revocation or expiration of, the notary public’s commission, or on the expiration of the date set forth in the stamping device, if any, the notary public shall disable the stamping device by destroying, defacing, damaging, erasing, or securing it against use in a manner that renders it unusable.

(c) On the death or adjudication of incompetency of a notary public, the notary public’s personal representative or guardian or any other person knowingly in possession of the stamping device shall render it unusable by destroying, defacing, damaging, erasing, or securing it against use in a manner that renders it unusable.

(2) If a notary public’s stamping device is lost or stolen, the notary public or the notary public’s personal representative or guardian shall promptly notify the department on discovering that the device is lost or stolen.