California Code, Public Utilities Code - PUC § 303

(a) A public utilities commissioner may not hold an official relation to, nor have a financial interest in, a person or corporation subject to regulation by the commission. If any commissioner acquires a financial interest in a corporation or person subject to regulation by the commission other than voluntarily, his or her office shall become vacant unless within a reasonable time he or she divests himself or herself of the interest.

(b) No executive of a public utility may serve as commissioner within two years after leaving the employment of the utility.

(c) The commission shall maintain an updated Conflict of Interest Code and Statement of Incompatible Activities in a manner consistent with applicable law.