Mac Repair Help

[nevmx]

This piece fell out of somewhere while I was disassembling my MacBook 13", does anybody know where it comes from/what it is?

 

[logana]

It fits into a small hole in the bottom case under the logicboard (just to the right of the Airport card....

If you have refitted the logicboard then I would not worry about it - if the logicboard is not in yet then refit it....