I'm usually a heavy sleeper. I woke up for no reason one night and looked at the bathroom located at the far right corner of my room. The light turned on and then turned off on its own. Right after a green orb came out of the washroom and floated into the hallway.What could it be?

How big was the orb? Was it tennis ball size? I have seen blue ones that size right before an abduction. Happened on several occasions and neighbors also saw it going around our house stopping at the windows.

Ball Lighning of some sort?

 have you had any other experiences like this, in my opinion and experience i would have to agree with godlypunk,  except to say if you had woken for no reason it may have been after the event, keep a journal, if you can remember the next time you awake in the night, just jot down time and its just a thought, but try and note how you were feeling, as it could help to build a bigger picture forearmed is forewarned

 hiya just a quicky, you mentioned a ball of light i had similar i thought i was imagining things, can you tell me did the light have a white tinge to it many thanks

Sounds like swamp gas to me lol, or a weather balloon may have been in your room and escaped.

Interesting. I've seen a blue ball of fire pass overhead, and a number of normal-looking flames (but very small ones that would start at a random point in the air, move up maybe a foot and disappear). No other signs of anything paranormal, but how many times can one person see ball lightning? :)