LYNN – A North Shore man was allegedly caught in the act Monday of stealing $20,000 worth of copper wires from a National Grid facility, police said.Todd Plante, 40, of 2 Hanson Road, Danvers, was arrested and charged with breaking and entering, larceny over $250, trespassing and malicious destruction of property shortly before 2:30 a.m.Police responded to 80 Marine Blvd. after a National Grid employee noticed Plante allegedly inside a fenced area.When officers arrived, Plante was allegedly placing spools of copper wire into the trunk of a parked car. Police noted that no businesses in the area were open at the time.Plante claimed he found the wire on the ground and was just placing it in his car, police said.The employee told police he watched Plante cut the wires off a spool and drag them toward his car.A National Grid employee told police the entire spool was ruined and would cost $20,000 to replace, police said.