"Haint" is a variation on the word "haunt." In parts of the Southern U.S., it was once common for porch ceilings to be painted blue in order to ward off spirits. The unique shade of blue used at the time was colloquially known as "haint blue." This piece is a play on that tradition, but here, the object is a door rather than a porch, and the door has been left ajar.
mightymoose
