A person who is employed by any common carrier or other public utility or who owns any bonds, stock, or property in any public utility shall not be eligible to hold the office of utilities board member or chief operating officer of the utilities board. A member or chief operating officer who enters into employment with any common carrier or other public utility or who acquires any stock or other interest in any common carrier or other public utility after appointment as a member or chief operating officer shall be disqualified from holding or performing the duties of the office.