Mich. Comp. Laws § 600.1430: Appearance in court by attorney or in person; exception.

Sec. 1430.

Every person of full age and sound mind, may prosecute or defend civil actions in any court by an attorney, or may, at his election, prosecute or defend civil actions in person. No person shall be permitted to prosecute or defend any civil action in person, when he has an attorney in such case.