Wis. Stat. § 196.33: Depositions.

The commission or any party in any investigation or hearing may cause the depositions of witnesses residing within or without the state to be taken in the manner prescribed by law for like depositions in civil actions in circuit courts. Any expense incurred or authorized by the commission in taking a deposition shall be charged to the appropriation for the commission under s. 20.155 (1) (g).