NEW YORK (Reuters) – New York City on Wednesday sued five companies it says are involved in the sale of illegal, largely untraceable “ghost guns” flowing into the city. In a complaint filed in Manhattan federal court, the city said the companies have created a public nuisance by selling “unfinished” firearms components that purchasers can build into guns, without undergoing background checks. The result is “a proliferation of unserialized, untraceable, unlawful ghost guns in the city’s streets and homes, making the City more dangerous for both the public and for law enforcement, causing a quin…