Michigan Compiled Laws, Chapter 330. Mental Health Code § 330.1411

Sec. 411.Subject to section 410, an individual 18 years of age or over may be hospitalized as an informal voluntary patient if he or she requests hospitalization as an informal voluntary patient and if the hospital director considers the individual to be clinically suitable for that form of hospitalization. Unless the hospital requires that the request be made in writing, the individual may make the request orally.