I believe it was Loyd Auerbach who noted: "Poltergeists do not happen in happy families."
(This begs the question of what was wrong in the Wesley household; but with so many kids, somebody was bound to be miserable.)
If this is true, then one would expect poltergeists in houses with long-term unresolveable stresses, like parents who ought to divorce and won't, an extended period of unemployment, or a member with a health condition that drags on forever.