Hi, I'm a 17-year-old senior high school student who lives in the Province of Leyte, Philippines. When our teacher dismissed our class at 5 p.m., I went with a few of my classmates to the school gymnasium to practice for our class presentation. It was quite dark in there, so we asked the security to turn on the lights. We were about to start our practice when I felt the need to go to the bathroom, so I asked one of my classmates, Brent, to accompany me.
We both went through a short hallway, and then I went inside the bathroom. It was so dark in there, so I turned on the light. While I was in the bathroom, I heard someone knocking on the door, so I said, "Someone is in here." When I went out to ask Brent who knocked, he said that no one was knocking and that he was just standing outside. We were both confused.
There was another knock, so we both turned towards the source of the sound. It was coming from another door. We walked over to the door and opened it. We saw the silhouette of a ghost under the light of the moon. We thought it was just a sheet of fabric being draped over a wooden mannequin. We didn't think much of it and rubbed our eyes to see if we were just hallucinating. We were not. A clear silhouette of a ghost was actually standing by the brightly lit window (the light was coming from the moonlight). We both left the area and went back to our practices.
The next day, there was a group of people talking about something, so we asked one of them to see what they were up to. He said that the ghost he saw last night was of a teacher that died in the school. The messy room was due to a poltergeist that haunted the school gymnasium, which probably explained the knocking last night.
I was hoping to read the link about the teacher dying in your school...oh, well... Sometimes silence says more than a thousand words.