A suspected explosive device found at a Lucerne home on Monday night was determined to be a harmless training grenade, located at a home in the 6200 block of Fourth Avenue. The Lake County Sheriff’s Office blocked the area near Fourth Avenue and Country Club Drive and called the Napa County Sheriff’s Office Bomb Squad. The item was X-rayed and was determined to be harmless. By 8 p.m., the area had been cleared.