Except as otherwise provided by law, the ethics boards may hold hearings, subpoena witnesses, compel their attendance, administer oaths, take the testimony of a person under oath, and in connection therewith, to require the production for examination of any books or papers relating to any matter under investigation or in question before the ethics board. The ethics board may make rules as to the issuance of subpoenas by individual members, as to service of complaints, decisions, orders, recommendations, and other process or papers of the ethics board.