Welfare and Institutions Code § 7103

The superintendent or person in charge of the county psychiatric hospital may admit and provide care and treatment in the hospital for any person who comes within the following descriptions:

(a) Who voluntarily makes a written application as provided in Chapter 1 (commencing with Section 6000) of Part 1 of Division 6 of this code.

(b) Who is a conservatee and has written application made in his behalf by his conservator.