Robert Reed thought the ghost story plot was stupid and refused to be in the scenes. The writers had him at meetings during the evening to write him out of the main ghost stories.
Carol insinuates that this is the same house Mike was in before they were married, however in the pilot episode it's clearly a different house as evidenced by the kitchen.
The episode establishes that Mike Brady had actually designed the house himself. However, the first episode of the series, "The Honeymoon" shows Mike and the boys residing in a completely different house. This presents some confusion over whether or not Mike built his own house, the home used in the series, before he married Carol or if he built the home afterward. It is never clearly explained.
The title is based upon the often used quote from Shakespeare's play 'Hamlet': "To be or not to be."