Michigan Compiled Laws, Chapter 600. Revised Judicature Act of 1961 § 600.1835

Sec. 1835.  (1) All persons going to, attending, or returning from, any court proceedings in any action in which their presence is needed are privileged from service of process if service could not have been made on them had they not gone to, attended, or returned from the proceedings.

(2) Any person brought into this state by or after waiver of extradition based on a criminal charge is privileged against the service of personal process in civil actions arising out of the same facts as the criminal proceedings which he or she is returned to answer until he or she has been convicted in the criminal proceeding, or, if acquitted, until he or she has a reasonable opportunity to return to the state from which he or she came.

(3) A member of the legislature shall not be privileged from civil process except on a day on which there is a scheduled meeting of the house of which he or she is a member.  However, a member of the legislature shall not be privileged from civil process on a day on which there is a scheduled meeting of the house of which he or she is a member, if such process is executed by certified mail, return receipt requested.