Wis. Stat. § 23.60
If the enforcing officer has stopped a person to issue a citation pursuant to s. 23.62 and reasonably suspects that he or she or another is in danger of physical injury, the officer may search such person for weapons or any instrument or article or substance readily capable of causing physical injury and of a sort not ordinarily carried in public places by law abiding persons. If the officer finds such a weapon or instrument, or any other property possession of which he or she reasonably believes may constitute the commission of a violation of those statutes enumerated in s. 23.50(1), or which may constitute a threat to his or her safety, the officer may take it and keep it until he or she has completed issuing the citation, at which time the officer shall either return it, if lawfully possessed, or arrest the person for possession of the weapon, instrument, article or substance, if he or she has the authority to do so, or detain the person until a proper arrest can be made by appropriate authorities.
Wis. Stat. § 23.60