It is just an announcement over the in park PA. If you are in the hub a small little twinkle show happens on the castle and then it is "kissed" out. I've seen it once and it made me warm and emotional. It was my last night of my CP and that is the only reason I stayed to experience it. I don't imagine I would have been so emotional had I not felt like I was really saying goodbye since it was not just a vacation that this was the end of.
The kiss good night may or may not happen. You can ask a manager or entertainment CM (most likely character attendant) later in the day to see if they know the time it will happen.