Longtime firefighter John Sylvester found himself in a precarious position Wednesday morning during the latest training exercise conducted by the city Fire Department. With wax paper covering his mask and only a limited amount of oxygen, Sylvester was tasked with weaving his way through a gauntlet of wires and obstacles spread throughout an empty house on Sagamore Avenue.Midway through the historic home, which was built in the 1730s, Sylvester became stuck in a tangle of wires purposefully placed in his way. But instead of panicking, the 24-year veteran firefighter was able to rely on his survival training and free himself from the mess of cords. Sylvester, who was dressed in full gear, then continued on through the rest of the home and eventually made it to safety by jumping through a first floor window. “That was tough,” Sylvester said while wiping sweat from his brow. The challenging scenario given to Sylvester on Wednesday represented the latest training exercise undertaken by local firefighters.