The move took place in the estate of a very wealthy old man so rich the president visited him regularly the house was gigantic and old school. The movie revolved around a small quiet late middle aged man who just showed up one day (walking with a cane) and the rich old man took an interest in him. In the movie the old rich guy had built himself a huge tomb/crypt and at the end the old man dies and naturally was put in his crypt. The little man spoke rarely and when he did he did so very softly, and exhibited mental retardation to a small degree.
I remembered a fireplace that was so huge it was about the size of a 2 car garage with a single single door jamb.

"Being There" with Peter Sellers