For the purpose of any investigation or hearing which the board is authorized to conduct, the board, or any member thereof, shall have power to administer oaths, take depositions, issue subpoenas, and compel the attendance of witnesses and the production of books, papers, documents, and other evidence. In case of the disobedience of any person in complying with any order of the board, or a subpoena issued by the board or any of its members, or on the refusal of a witness to testify to any matter regarding which he or she may be lawfully interrogated, the judge of any district court of the county in which the person resides, on application by any member of the board, shall compel obedience by attachment proceedings as for contempt, as in the case of the disobedience of a subpoena issued from such court or a refusal to testify therein. The sheriff of the county in which such person resides shall serve all orders and subpoenas herein referred to. Each witness who shall appear in obedience to a subpoena before the board or a member thereof, shall receive for his or her attendance the fees provided for witnesses in civil cases in the district court of this state and mileage at the rate provided in section 81-1176 for state employees, which shall be paid upon the presentation of proper vouchers, approved by any two members of the board. No witnesses subpoenaed at the instance of a party other than the board or one of its members, shall be entitled to compensation unless the board shall certify that his or her testimony was material to the matter investigated.