I have had this happen before and the goal is to contain the damage once the water is inside. If the water starts dripping through the ceiling, drill a small hole, (1/4", and recommend a battery drill, to minimize chances of electrocution

), and let the water drain out into a bucket. You want to get it out of the ceiling and stop it from spreading and try to contain the damage. Don't worry about the hole in the ceiling, as it will have to be repaired anyway as a result of the water drip damage.