Preservationists and property owners are fighting over Wardenclyffe, a site in Shoreham, N.Y., that includes an early wireless tower and laboratory used by inventor Nikola Tesla. The tower, constructed in the first few years of the 20th century, was part of a system intended to relay electricity, news, stock reports and pictures through the air. A science group wants to turn the Long Island property into a museum and education center, but the owner, Agfa Corporation, wants to sell the property to raise money. The land is listed for $1.6 million, and the real estate broker has proposed to clear the land.