The open house movie is about a teenage girl who was molested by her father calls David Kelley, a radio psychologist working for KDRX, and shoots herself in the air. Later, a real estate broker shows off a house to prospective buyers and discovers the decomposing remains of another realtor in the washroom, the fourth victim of a psychopath dubbed the Open House Killer.

The Vagabond goes to one of the listed houses, and murders the realtor and buyer inside with a plunger that has had razor blades attached to it. The Open House Killer (who gives his name as “Harry”) then calls David at KDRX and opines that his victims deserved their fates.

After an open house, Harry breaks into the property and electrocuted the realtor with frayed wires

As Harry continues to make rambling calls to KDRX, a detective named Arnold Shapiro is assigned to work with the station to try and track Harry down. In trying to protect their employees, the real estate agencies start new safety precautions, though these do little to deter Harry, who murders another agent by hanging her.

The next day, Harry abduct Lisa, who gives cryptic hints about her whereabouts when Harry calls KDRX to taunt David. David tracks Lisa and Harry to an empty house, and as the authorities swarm the building,

Harry expresses disappointment over the media not being present, and rants about how corporations and the real estate industry drove him to kill, as they made it so he could never have a place he could call his own. Just as Harry is about to slit Lisa’s throat, he is shot and knocked through a glass door by Detective Shapiro. Despite the severity of his injuries, Harry still tries attacking and is finally killed when Shapiro knocks him off a balcony.

Culled from Wikipedia | Open House (1987 film)