California Code, Civil Code - CIV § 1695.4

(a) In addition to any other right of rescission, the equity seller has the right to cancel any contract with an equity purchaser until midnight of the fifth business day following the day on which the equity seller signs a contract that complies with this chapter or until 8 a.m. on the day scheduled for the sale of the property pursuant to a power of sale conferred in a deed of trust, whichever occurs first.

(b) Cancellation occurs when the equity seller personally delivers written notice of cancellation to the address specified in the contract or sends a telegram indicating cancellation to that address.

(c) A notice of cancellation given by the equity seller need not take the particular form as provided with the contract and, however expressed, is effective if it indicates the intention of the equity seller not to be bound by the contract.