(1) Except as is provided in section 420, a formal voluntary patient 18 years of age or over shall not be hospitalized or provided mental health treatment for more than 3 days, excluding Sundays and holidays, after the patient, the full or limited guardian with authority to consent to mental health treatment, or a patient advocate authorized by the individual to make mental health treatment decisions under the estates and protected individuals code, 1998 PA 386, MCL 700.1101 to 700.8206, gives written notice of an intention to terminate the patient’s mental health treatment.

  (2) When the hospital or provider of mental health treatment is told of an intention to terminate mental health treatment under subsection (1), it shall promptly supply the written form that is required.