I was having an annual camp with my ECA in a secondary school in Toa Payoh in 1999. Like any other old school, it was filled with rumours and ghost stories at many of the places such as toilets, classroom. We were just finished with the campfire on the last night of the 3-day, 2-night camp. Sentry duties were to be conducted by the campers as usual in any other camps. Being instructors, we have to prowl the area once to ensure that there are no other unwanted personnel around. I was rather sceptical about ghosts in schools as I have never seen any of it and was eager to go through the whole thing to prove to myself that there was no such paranormal things in old school like this. I gathered 4 instructors with me and we decided to go to every locations and corners in the school, no matter how dark or sensitive the places are. First, we prowl the first floor from the back of the buildings to the field. Along the way, we check the fences, just outside the classrooms area and surroundings. Those classroooms with opened windows were being looked through and every tree in the area were being checked. We came upon the small hut behind the P.E building and found the metal door closed. As we have to ensure that no one was inside, I took a stick and slowly pushed the door open, by now, half-expected to see something which I don't believe. As the door slowly creaked to open, we discover there was nothing inside other than the usual cleaning equipment. As we smiled to our silliness, we walked away, only to hear the old metal door closed again. We were rather shocked, but told ourselves that it was the hinges to close the door, not daring to check it out again. The same thing goes for the 2nd and 3rd floor classrooms and corridors till we reaches the 4th floor toilet, which is one of the most famous ghost haunts. Every year, one of the campers will report seeing something hanging along the corridors just outside it. We check out both the gents and ladies but turned out fruitless.
After we have finished with our routine prowling, we sat at the leftovers of the campfire, discussing that there was nothing wrong with this school afterall. Suddenly, the only girl instructor with my group, pointed out to us that she saw someone looking at the back of the first classroom when we were prowling at ground level at back of the buildings. She didn't dare to tell us at that time as she always have bad experiences with these stuff and don't want bad things to happen to her then. I immediately jumped up and got one of the guy instructor to follow me to the classroom said. On our way there along the corridors outside the home econs lab, I felt the hairs on the back of my head standing on their ends. Not wanting to alert my partner, we headed to the classroom, check out everything and discovered nothing. We went back to join the rest of the team. Back at the campfire, I asked my partner whether he felt anything during the second round to the classroom. To my amazement, he told me that he felt his back hairs standing at the exact location where I experienced the feeling. (I did not told him about my experience as I wanted to ensure that he did not try to scare me). My friends, who were the old students from the school told me that the spirit(s) were friendly ones who will not disturb us as long as we did not disturb it. To be sure, we went back and switched on the corridor lights at the 'spot'. This time, we felt nothing like just now. My friends told me that the spirit has gone away for a while and we should not disturb the calmness of the area. The whole night was peaceful, as none of the campers has reported any sightings which was a relief to us.