Mich. Comp. Laws § 767.8

Sec. 8. Any court in which a grand jury may be sitting, may discharge any of the grand jurors for intoxication or other gross misconduct; and in case of such discharge, or in case of the sickness, death or non-attendance of any grand juror, after he shall have been sworn, the court may cause another juror to be summoned from among the bystanders, or inhabitants of the city, township or village having the qualifications required by law, and to be sworn and to serve in his stead.