Cal. Food & Agric. Code § 65567

In the event the office of a commissioner becomes vacant due to failure to qualify, resignation, disqualification, death or for any other reason, such position shall be filled by an election held by the commission. Nominations shall be received by the commission from the remaining commissioners in the district where the vacancy exists. An election shall then be held by the commission and a majority vote shall elect a commissioner, subject to appointment by the director, to fill out the unexpired term for which such election is being held. Vacancies occurring within six months prior to a regular district election may remain vacant until the next regular election. Commission members elected at special elections shall serve the unexpired term of the office to which they are appointed.