Wis. Stat. § 941.12: Interfering with fire fighting.

(1) Whoever intentionally interferes with the proper functioning of a fire alarm system or the lawful efforts of fire fighters to extinguish a fire is guilty of a Class I felony.

(2) Whoever interferes with, tampers with or removes, without authorization, any fire extinguisher, fire hose or any other fire fighting equipment, is guilty of a Class A misdemeanor.

(3) Whoever interferes with accessibility to a fire hydrant by piling or dumping material near it without first obtaining permission from the appropriate municipal authority is guilty of a Class C misdemeanor. Every day during which the interference continues constitutes a separate offense.