If there is no lease, then you may be on a month to month agreement, so looking at your lease is very important.
Here is a Guide from the State of Michigan http://www.legislature.mi.gov/documents/publications/tenantl -
Talk to your landlord - and see if they would be open to this possibility. Essentially you do the job of renting the place while you still live there, and as soon as your potential new tenant is approved by the landlord - you can get out no problem.
At the end of the day - landlords simply want to know that they have cash flow coming in from thier property, without disruption. Whether it's coming from you - or somebody else, as long as that stream of money keeps coming in and they know thier property is being taken care of, they'll typically be pretty flexible.
I would read the lease if I were you and see if there is a clause that may enlighten you further...Hope that helps!