This is my first post here so I hope it's okay.
Just a little background, I spent the first 10 years of my life in Singapore, (I'm now 14. Yeah.) And I moved to Australia right before my 10th birthday. I first went to the school in this story in year 1, and I started experiencing these things, and not just me, it happened to several of my fellow classmates as well.
The first experience I went through was when I was 7-8. I was in the bathrooms after school, getting changed, when someone started shaking the cubicle door very violently. Thinking it was one of my friends playing a prank on me, I ignored it and it stopped after a minute. Before entering the bathroom, you'd have to push open a door which squeaks very loudly and there was no one there before I entered. I walked out of the cubicle and there was no one else there.
It was after this when some of the older kids began telling 'rumors' that the school was haunted, telling of their experiences. Most of them were things like doors slamming shut and footsteps in empty corridors and I didn't believe them much.
A few weeks after, I went to a festival held at night. A friend and I dashed up to our lockers on another floor to retrieve something. We had lockers next to each other so we both had our backs to the open corridor. At first, there was only a buzzing from the light. There was a click and the light went out, then the two of heard footsteps running behind us and felt the wind brushing against our backs as if someone had in fact sprinted past us. When the footsteps had passed, the light went back on. We were both alone and the corridor was shaped in a curve with the inside wall being lined with windows so we could see all along the corridor and we couldn't see anyone else along the whole stretch.
In other events, I have been pushed down several flights of stairs by an unseen force, and my friends have heard voices in empty rooms.
But by far, the most disturbing experience was not mine, but it was experienced by a close friend of mine. She had lost her mother when she had drowned a few weeks ago and was wearing a black badge in honour of her. She had lost the badge a day ago and we were trying to find it around the school. She walked into the bathroom while I searched around the canteen. When I met back up with her, she was in tears, clutching her badge. When I asked her what had happened, she said that when she had entered the bathroom, she heard a voice scream her name and the badge had fell on her head.
I haven't had an experience since leaving Singapore and I am glad that I haven't.