The FBI is working with the U.S. Postal Service to determine whether Empire actor Jussie Smollett sent himself a threatening letter in the days before the “hate crime” he is now under investigation for allegedly staging, two federal officials told ABC News Tuesday. The two Nigerian brothers who told Chicago Police last week that Smollett paid them to stage a racially motivated attack on him have also told the authorities that Smollett sent himself the threatening letter that arrived on the Empire set on January 22, just seven days before they claim they conducted the hoax attack. The brothers, one...