Nah, such services already exist. You just have some extremely loutish, heavy-hitting-seeming dude "move in" with the squatter with a legit lease. The mission is to be so foul and unpleasant that the original squatter leaves.
In other contexts due to jury nullification, prosecutorial misconduct and similar you might actually see vigilante groups for hire. The opening scene from The Godfather was based on reality.