To recover your earring, ensure that you do not run water in the sink. Doing this would cause the earring to be washed further away. Check below the sink and you will see a curve piece under the trap. If the trap is of plastic, you can turn it off by hand. Before opening, put a bucket under the trap to collect the water that will pour. For more information, visit http://www.ehow.com/how_5566404_recover-earrings-bathroom-sink-drain.html.