Some months ago I saw this ball of light floating out of my sisters room. It wasn't like those small orbes you see in some photographs, it was much bigger, a little smaller than a volleyball and very clear and bright. It just floated out of my sisters room and after a little while of floating around it just disappeared and I never saw it agan.
So here is my question; what was it? I have asked other people, but I never got fulfilling answers.

So I hope you can help me  

I have other questions allso butI think I'm going to save them for later

Thank you very much

How was the wether?
Can it have been a "ball lightning" ? they can behave very strange ...have I heard...can it have been some eletrical reason for it?

the weather was clear and lightnings are not very common where I live. And it had this very plesant feeling with it. I am a very suspicious person so I checked if there was any locical explenation, but I couldn't see anythingthat could have caused this.

I also have seen a ball of soft white light same in size.  This was around 1988-89.  My husband was out of town and as I sat on the couch watching TV something to my left caught my attention as I turned to look there was the transparent white ball that went through the door and out into the garage.  I felt like something had left me.  Did not scare me and I continued to watch TV. Although I wondered if it couldn't have been a car going by and what I had seen was from the car's lights.  I am still not sure.  One more thing to add to this story.  You know how you feel after watching a scarey movie and your on your way to bed?  Like something is behind you or going to get you.  Well that is sorta how  I felt those couple of days that my husband was gone.  I remember feeling like I was not alone, but felt peaceful, not threatened even felt as if someone was walking behind me.  Just there to possiblly watch over me.  These feelings were only for a couple of days out of the 4/5 days that my husband was gone.  By the way I have not ever been afraid of being by my self and do enjoy my quiet times.  Some things we will just never know and I believe we are not to know.

There does not need to be lightning in the area (apparently) for ball lightning to occur, and has also been known to occur indoors check this link out : http://www.crystalinks.com/ball_lightning.html