Cal. Gov. Code § 8940
The Joint Legislative Ethics Committee is hereby created. The committee shall consist of three Members of the Senate and three Members of the Assembly who shall be selected in the manner provided for in the Joint Rules of the Senate and Assembly. Of the three members appointed from each house, at least one from each house shall be a member of the political party having the largest number of members in that house and at least one from each house shall be a member of the political party having the second largest number of members in that house. The committee shall elect its own chairman. Vacancies occurring in the membership of the committee shall be filled in the manner provided for in the Joint Rules of the Senate and Assembly. A vacancy shall be deemed to exist as to any member of the committee whose term is expiring whenever such member is not reelected at the general election.
Ca. Gov. Code § 8940