What is this bolt? And should it be partially unscrewed?
 

Noticed this while changing oil. What is it and should it be like this? For reference I pointed the arrow at the oil filter so that you can tell where it is. Left side of the picture is the oil pan, the drain bolt is just out of the picture.

http://imgur.com/a/r0wEc

Almost positive it's an oil pressure switch. If it was loose, you'd be leaking oil. Mitsubishi used the same switch in many different cars, so it's just designed with long threads that some cars may need, while others may not.