No carry of any kind in a courthouse. Courthouses were never declared PFZs by the legislature but instead fall under judicial authority, and therefore the "normal CEZ OC situation" would never have applied anyway. Rather, the Michigan Supreme Court has declared that weapons are not permitted in any space used for court business which, I assume, extends to a courthouse as a whole, and their word on the subject is final.
From the MSP:
"Effective March 29, 2001, per Administrative Order 2001-1 of the Michigan Supreme Court:
"Weapons are not permitted in any courtroom, office, or other space used for official court business or by judicial employees unless the chief judge or other person designated by the chief judge has given prior approval consistent with the court's written policy.""