Wait and watch. What a silly bird - is it a jackdaw or a magpie or something like that? They don't usually SWALLOW things that aren't edible. It may come out the other end, or it may be storing it in its crop, so it might just regurgitate it after a while. I don't think there's anything you can do which wouldn't harm the bird more than the earring would.

 Birds have surprisingly tough guts. The chances are that the earring is lodged in the birds gizzard, and it is happily using it, along with bits of grit, to grind up its food.

 What are you doing feeding your bird earings? It wont increase in value. No just kidding. Gosh i hope it wasn't very big cuz really the only thing you can do is keep an eye on its droppings. You wont like the other option trust me.but the best thing to do is call your nearest pet store that specializes in birds.