Cute a piece of material in a circle shape, one that will fit around the foam ball.
Cut 4 slits around the edges so that when you wrap the material around the ball, they will overlap each other.
Wrap and hot glue the material over the foam ball.
Wrap one loop around the wall with wire, and twist the ends together. Continue wrapping the ball with wire until satisfied.
Twist the ends together again, and cut off, leaving enough to loop through a chain link.
Using plyers, make the chain as long as you want.
Wrap the wire ends through the end of one link, and using plyers again, attach the other end to an earring.