Homeless Guy -- I Got Paid $40 to Appear in Justin Timberlake Wedding Video

One of the homeless men who appeared in a video reportedly featured at Justin Timberlake's wedding says he was paid $40 ... and had NO IDEA he was the punchline in a sick joke.

TMZ spoke with the man -- "Eddie" -- who tells us he was just minding his own business in Hollywood when he was approached by a man who offered him money in exchange for saying a few pre-written lines into the camera.

Eddie says the cameraman told him the video was being made for a friend's wedding -- Eddie had no idea it was for Timberlake and Jessica Biel.

When we told him how the footage was used, Eddie told us, "That makes me feel really bad ... that was a trick played on me."

In case you're wondering why Eddie is dressed so nicely in our video -- it's because he was out looking for a job yesterday.

"I'm gonna do my best to change my life."