I own a house that my boyfriend lives in we have a child together and he has not paid for mortgage or monthly bills for the past 12 years does he have any rights to stay on the property

If he does not have a lease, and if his name is not on the deed. He has the same rights of any "renter" * even if not paying rent. He would have to be evicted.

Does Michigan have common law and if so how many years does it take

Michigan does not have common law marriages, no length of relationship would qualify as married so you must follow Michigan laws to evict. Michigan Evictions (http://www.rentlaw.com/eviction/mieviction.htm)