Joseph Sheridan Le Fanu 
Evil Guest 

The letter from the rich cousin came at a low point in the Marston family’s finances. The man was as ill-bred and pushing as ever: utterly the model of a noxious relation — but he was rich, and the Marstons were all but destitute. The family could hardly refuse him. But they would come to rue that letter, and the invitation that followed it; it was the beginning of the end for all of them. Of course it was! Common sense tells us not to take on . . . "The Evil Guest". (Goodreads)