"Nove Ospiti per un Delitto" is a mediocre giallo in the tradition of Agatha Christie's "And Then They Were None". Nine members of the same family go to an island, where nobody lives - but the head of the family (Arthur Kennedy) owns a nice house there. Problem is that he and his three sons keep a dark secret, and this dark secret begins to haunt them as soon as they are on the island. One by one they fall victim to a mysterious killer... (IMDb)
Every year, a family home is turned into a haunted house. The purpose is not only to be as terrifying as possible, but also to create a spectacular attraction to draw the neighbours in. In response to some criticism, the father commits irreparable damage.