Have you ever seen ghosts?

In my religion ghosts are very real but the only come out at night. Once when I was little and walking home after visiting a relative I saw a an old woman who was floating in the air, inches away from my face. She looked angry and I ran as fast I could. She tripped me but I still ran and never saw her again once I got home. I still remember this incident vividly, but I wonder if it was just an illusion.