Cal. Welf. and Inst. Code § 11351.5
Whenever an unrelated adult male resides with a family applying for or receiving aid under this chapter, he shall be required to make a financial contribution to the family which shall not be less than it would cost him to provide himself with an independent living arrangement.
The minimum financial contribution to the family shall be determined in accordance with standards established by the department which takes into account such adult male person's income and expenses. The regulations formulated by the department shall require the mother of the children and the unrelated male to present all of the facts in connection with the sharing of expenses which comprise the agreement whereby said adult male resides with the family. The conditions of the agreement and the facts related to the sharing of the family expenses shall be signed under penalty of perjury by both the mother of the child and the unrelated male. In the event that either the mother or the adult male person willfully and knowingly fails to cooperate during the period such joint sharing of expenses arrangement exists in setting forth all of the facts in accordance with provisions of this section, aid to the family may be discontinued.
The provisions of this section do not apply to a bona fide paying lodger, roomer or boarder living in the home of a family applying for or receiving aid under this chapter.
Ca. Welf. and Inst. Code § 11351.5