Beam of Light

I go to a boarding school, and apparently it's haunted, by many things. I have yet to encounter anything, but my friends have. Even though I have maybe seen things out of the corner of my eye, I'm not quite sure I believe it yet, but one thing that really weirded me out was this: My friend and I were walking on a hill, that is behind our school at night, just looking at the stars and talking.

Now, behind our school is a big forest, that is very spooky at night, and we were in front of it. I saw a beam of light move very quickly across the trees but of course I thought it was just my eyes playing tricks on me so I didn't really think much of it. My friend right after I saw it, then said "Oh!" I turned to her, and asked what? She said she forgot something (I can't remember what she said exactly) and I got alittle disappointed because I thought she had seen the same thing, I looked down and then she asked me what was wrong? I told her I thought she saw something, and then she looked at me, and asked me if it was the beam of light. I was scared but yet excited, she saw it too, but she had also just thought it was her eyes playing tricks on her.

I don't know what it could be, just a orb? Please, say your thoughts!