Wis. Stat. § 780.05
In case the plaintiff's claim arises out of or is founded upon any of the causes under s. 780.01(1) or (5) the plaintiff shall not be required to give the undertaking required by s. 811.06 unless required so to do by an order of the court or judge; and no such order shall be made unless the defendant or someone in the defendant's behalf shall make an affidavit showing that he or she has a good and valid defense in whole or in part to the claim or demand of the plaintiff, setting forth the nature of the defense; and where the defense is only to a portion of the claim, before any such order shall be made the defendant shall pay or tender to the plaintiff that portion of the claim to which there is no defense; such payment or tender shall not affect the jurisdiction of the court or prevent a recovery by the plaintiff of the same costs, disbursements and charges as the plaintiff would have been entitled to had not the amount of the plaintiff's claim been reduced by such payment. No such order shall be made except upon one day's notice to the plaintiff, accompanied by copies of the affidavits and other papers upon which it is founded.
Wis. Stat. § 780.05