WIS. STAT. ANN. §66.0301. Intergovernmental cooperation
(1)(a) Except as provided in pars. (b) and (c), in this section “municipality” means the state or any department or agency thereof, or any city, village, town, county, school district, public library system, public inland lake protection and rehabilitation district, sanitary district, farm drainage district, metropolitan sewerage district, sewer utility district, solid waste management system created under s. 59.70(2), local exposition district created under subch. II of ch. 229, local professional baseball park district created under subch. III of ch. 229, local professional football stadium district created under subch. IV of ch. 229, local cultural arts district created under subch. V of ch. 229, long-term care district under s. 46.2895, water utility district, mosquito control district, municipal electric company, county or city transit commission, commission created by contract under this section, taxation district, regional planning commission, housing authority created under s. 66.1201, redevelopment authority created under s. 66.1333, community development authority created under s. 66.1335, or city-county health department.
WIS. STAT. ANN. §66.0303 Municipal interstate cooperation.
(1) In this section, “municipality” has the meaning given in s. 66.0301(1)(a), except that with regard to agreements described in s. 66.0304, “municipality” includes a political subdivision, as defined in s. 66.0304(1)(f).
(2) A municipality may contract with municipalities of another state or with federally recognized American Indian tribes or bands located in another state for the receipt or furnishing of services or the joint exercise of any power or duty required or authorized by statute to the extent that laws of the other state or of the United States permit the joint exercise.
(3) (a) Except as provided in par. (b) and s. 66.0825(18), an agreement made under this section shall, prior to and as a condition precedent to taking effect, be submitted to the attorney general who shall determine whether the agreement is in proper form and compatible with the laws of this state. The attorney general shall approve any agreement submitted under this paragraph unless the attorney general finds that it does not meet the conditions set forth in this section and details in writing addressed to the concerned municipal governing bodies the specific respects in which the proposed agreement fails to meet the requirements of law. Failure to disapprove an agreement submitted under this paragraph within 90 days of its submission constitutes approval. The attorney general, upon submission of an agreement, shall transmit a copy of the agreement to the governor who shall consult with any state department or agency affected by the agreement. The governor shall forward to the attorney general any comments the governor may have concerning the agreement.
(b) An agreement under this section between a municipality of this state and a municipality of another state that relates to the receipt, furnishing, or joint exercise of fire fighting or emergency medical services need not be submitted to or approved by the attorney general before the agreement may take effect.
(4) An agreement entered into under this section has the status of an interstate compact, but in any case or controversy involving performance or interpretation of or liability under the agreement, the municipalities party to the agreement are real parties in interest and the state may commence an action to recoup or otherwise make itself whole for any damages or liability which it may incur by reason of being joined as a party. The action by the state may be maintained against any municipality whose act or omission caused or contributed to the incurring of damage or liability by the state.