Subscribe | UPI Odd Newsletter Subscribe MILTON, Mass., March 25 (UPI) -- Authorities in Massachusetts said a former landlord discovered a house he is planning to sell was rigged to explode with the flip of a light switch. Milton Police Chief Richard G. Wells Jr. said Tuesday homeowner Lendel Williams, his attorney and an electrician were conducting a pre-sale inspection of the house, which was recently occupied by renters, when they discovered an apparent explosive device wired to one of the home's light switches. Advertisement "We believe the intention was that if someone had flipped the light switch on where it ended, the device would have exploded," Wells said. He said the device had several wires that spread through multiple rooms and were connected to a gallon container of an incendiary substance. "It took some work to put it in there," he said. A bomb squad was called in from Boston to render the device safe, police said. Wells said police were called to the home last week on a vandalism complaint. Officers arrived to find the drains had been plugged with concrete. Williams said the renters moved out of the home Sunday. "I am angry," Williams told WCVB-TV. "I just can't believe people can really do that to be quite frank with you." Advertisement Police said they are trying to get in contact with the former residents of the home and anyone with access to the house is being considered a person of interest in the case. Read More Experts: Fla. firm's medical pot loophole claims a pipe dream Trooper: 'Most Interesting' HOV cheat used cardboard cutout Elephants hold up tipping tractor-trailer in Louisiana Cat's crazy car cruise caught on camera in Ohio