Cal. Const. art. VI § 17
A judge of a court of record may not practice law and during the term for which the judge was selected is ineligible for public employment or public office other than judicial employment or judicial office, except a judge of a court of record may accept a part-time teaching position that is outside the normal hours of his or her judicial position and that does not interfere with the regular performance of his or her judicial duties while holding office. A judge of a trial court of record may, however, become eligible for election to other public office by taking a leave of absence without pay prior to filing a declaration of candidacy. Acceptance of the public office is a resignation from the office of judge.
A judicial officer may not receive fines or fees for personal use.
A judicial officer may not earn retirement service credit from a public teaching position while holding judicial office.
Cal. Const. art. VI § 17