(1) Subject to Act No. 267 of the Public Acts of 1976, the commission and each commissioner and each person designated by the commission may hold public or private hearings within the state, subpoena witnesses and compel their attendance, administer oaths, take testimony, and receive evidence. A subpoena may be issued only after the mediation of a dispute shall have been actually undertaken.

    (2) If a person is contumacious or refuses to obey a subpoena issued to the person, the circuit court of a county within the jurisdiction of which the inquiry is carried on, upon application by the commission, may issue to the person an order requiring the person to appear before the commission, to produce evidence or to give testimony touching the matter in question. Failure to obey an order may be punished by the court as contempt.

    (3) Process and papers of the commission may be served either personally or by registered mail or by telegraph or by leaving a copy at the principal office or place of business of the person to be served. Return by the individual serving the same setting forth the manner of the service, return post office receipt or telegraph receipt for the service, shall be proof of service of the same.