Mich. Comp. Laws § 45.95

Sec. 15. No account for goods, wares or merchandise purchased by any officers created by this act, shall be paid, unless sworn to as required by law, which affidavit shall further state that no commission or other compensation has been or will be paid as a consideration for such purpose. The said purchasing agent shall be provided with offices at the county seat. It shall be the duty of the board of supervisors or board of auditors to provide the said agent with the necessary stationery and office equipment in the manner now in force in the various county departments.