ANDOVER — Police in a northern Massachusetts town say a political campaign sign supporting Donald Trump was mistaken for a bomb.Chief Patrick Keefe says a bicyclist passing the sign Thursday afternoon thought a plastic box attached to it looked suspicious. The sign was in front of a home on Jenkins Road near the North Reading town line.The large, heavy wooden sign was mounted on two metal poles, one of which had a plastic box on it with "Do Not Touch" written on it, according to police.