Cal. Prob. Code § 405

Notwithstanding Section 404, the Controller may, at the Controller’s pleasure, revoke the appointment of a person to act as a probate referee. Under this section, the Controller may revoke the appointment of not more than 10 percent of the probate referees in each county in any one calendar year, but may revoke the appointment of at least one probate referee in each county in any one calendar year.