Spray bottle might work, but the trick is to make sure the cat doesn't realize one of the humans was responsible. In other words, you're going to out-stealth the cat because some of them do hold grudges. I have a cat who gets particularly loud in the middle of the night, but sometimes she just wants me to get up and play. Also, if the cat's vocalizations are rewarded during the day time - *cough* I talk back to my cat sometimes *cough* - you're providing reinforcement. Cats are smart enough to learn when talking is and isn't appropriate though, so there's fortunately no need to give the cat the silent treatment. What you might want to try is keeping window blinds or curtains open so the cat has something to watch while you sleep. Also, if there are any closed doors inside the house... leave them open and let him explore.