Wis. Stat. § 180.0742: Demand.

No shareholder or beneficial owner may commence a derivative proceeding until all of the following occur:

(1) A written demand is made upon the corporation to take suitable action.

(2) Ninety days expire from the date on which the demand was made, unless the shareholder or beneficial owner is notified before the expiration of 90 days that the corporation has rejected the demand or unless irreparable injury to the corporation would result by waiting for the expiration of the 90-day period.