Me. Stat. tit. 14 § 501
Personal and transitory actions, except process of foreign attachment and except as provided in this chapter, shall be brought, when the parties live in the State, in the county where any plaintiff or defendant lives; and when no plaintiff lives in the State, in the county where any defendant lives; or in either case any such action may be brought in the county where the cause of action took place. Improper venue may be raised by the defendant by motion or by answer, and if it is established that the action was brought in the wrong county, it shall be dismissed and the defendant allowed double costs. When the plaintiff and defendant live in different counties at the commencement of any such action, except process of foreign attachment, and during its pendency one party moves into the same county with the other, it may, on motion of either, be transferred to the county where both then live if the court thinks that justice will thereby be promoted; and be tried as if originally commenced and entered therein. Actions by the assignee of a nonnegotiable chose in action, when brought in the Superior Court or in the District Court, shall be commenced in the county or division when brought in the District Court, in which the original creditor might have maintained his action. [1973, c. 378(AMD).]
14 M.R.S. § 501