If your unit appears to be abandoned there are several steps you should take to as a landlord. The first step is to determine if the unit is truly abandoned, or if the tenant has just left for an extended period of time and forgot to tell you. A tenant's abandonment may be determined by the return of keys, the substantial removal of their personal property, notice by the tenant, the extended absence of the tenant while rent remains unpaid, or any evidence which would cause a reasonable person to believe that the tenant has surrendered possession of the rental unit.
If a tenant has abandoned the unit the landlord does not have to accept the abandonment as a surrender or a termination of the tenant's obligations under the rental agreement. At the landlord's option, the landlord can relet the premises and hold the tenant liable for any difference between the rent that would have been payable for the remainder of the term, if the original rental agreement had continued, and the net rent realized by Landlord by reletting to another tenant. Again, this is at the landlord's option but it is intended to protect the landlord in the event a reletting is not as economically attractive as the original, abandoned agreement.
Michigan law does not specify a procedure for handling personal property left behind in an abandoned rental unit.
Because of that the default position is that the landlord can consider any personal property left on the premises to have been abandoned, and the landlord may dispose of all personal property in any manner he deems proper. This language should be included in the lease, along with a statement that the tenant relieves the landlord of all liability for handling the personal property. When signing a lease with a tenant in Michigan, make sure to point out that very important clause so that they are aware of the consequences of leaving personal property behind.