A security guard at Aqueduct Racetrack was charged Monday as the “inside man” in the armed heist of more than $280,000 in gamblers’ lost wagers — as the feds alleged that he was busted with one of the crooks in another robbery more than 20 years ago. Lafayette Morrison was charged with providing Lamel Miller and another accomplice with information about when and where the money would be taken to the vault at the Queens racetrack following the lucrative “Gotham Day” races on March 7.