It so happen to 2 of my friends... It happen in the afternoon of this particular day...
2 of my friends went to the toilet of our school and tie their hairs...just then...one of them heard footsteps in one of the toilet cubicles...Later they heard the flushing of the toilet...Out of curosity, they knock on the door...They found out that the door was not locked...so they open the door...and they saw nothing.
Who could have flushed the toilet? Nobody knows...