Wis. Stat. § 813.05: Notice required.

(1) An injunction shall not be allowed after the defendant shall have answered, unless upon notice or upon an order to show cause; but in such case the defendant may be restrained until the decision of the court or judge granting or refusing the injunction.

(2) In an action against an insurance company or fraternal benefit society for an injunction or a receiver the commissioner of insurance shall be notified. Mailing a copy of such notice addressed to the commissioner of insurance at Madison, Wisconsin, shall be sufficient service.