strange water

Call it paranormal, but what I encountered is sure not normal. My office ceiling softboard was suddenly dripping water like a tap. We thought there is a leak from a pipe within. So we called in the maintenance people, which when they arrived the leak seems to have stopped. They opened up the ceiling board and found the place to be dry. There is no leak on any pipes, which is only small and use for the fire spray. So the mystery remains, where the water come from.