Glowing Light Blue Sign Or Ghost

This is strange to me. I don't even know what to call it. I have been experiencing strange things in my house since November 2009. First in November 2009, I was sleeping when all of a sudden I felt like something was biting me on my shoulder. I couldn't move at all. I was so scared and couldn't do anything. I called my friend immediately and she told me to bless my home.

The next morning I called my pastor and he came over to bless the house. He also told me that I needed to keep blessing the house because some evil is stronger than other forces. So I only blessed it once, thinking it was over. But now, last night May 17, at 3am, I woke up to check on my kids because my daughter hadn't come home. When I walked to their rooms I turned the corner and I was so shockingly amazed at what I was looking at. I just stood there, felt nothing a little startled. There it was on the floor a circle with a V in it, like a symbol and it looked like a fluorescent light blue color. All I can do is reach over to the light switch and turned it on. I had to wake my best friend up to tell her what happened to me. She just said it could have been a ghost and to pray immediately. She told me to rebuke and bless my home. I don't know what that was.

Can you please give me answers?

I don't know what to do and especially if it happens again.

Please Help.