Mike Yack has left the workforce twice in the last eight years and calls himself retired, yet at age 62 the former General Motors employee does not consider his working life over. “I’d be open to anything — learning a new trade or something. I don’t expect top wages. But I am not going to work for $10 an hour,” said Yack, who accepted a buyout from GM in 2006 and was then laid off earlier this year by a GM contractor. Yack, who says he can get by on Social Security and his GM pension, is among millions of Americans who could re-enter the U.S.