In The Wizard Comes to Town by Mercer Mayer, a stranger rents a room at Bertha Beggs's boarding house. Things quickly go awry, from rainstorms in the parlor to reptiles in the beds, until Mrs. Beggs decides she must expel her unusual lodger with some spells of her own.
Mercer Mayor, published 1973, later released as “The Wizard Comes to Town”