BeBoSON is correct, you WILL need drainage for a chameleon. Its just kinda mandantory for indoors

I have a mistking, I run two nozzles in a cage, and one nozzle on my wall in a free range setup. There is ZERO water that comes out of the 2x2x4 cage, thats with two nozzles. They sell a regulator valve that comes with the ultimate setup to adjust the spray if your worried about it. I use one on the freerange nozzle. It turns on 8 times a day, for a total of probably 20-30min total. I have no issues with water going where I dont want it to. Just drill a hole in the bottom of the cage, and put a bucket/tote bin to collect it.
EDIT:
I dont use a shower curtain or anything on the outside of the cage, just direct the nozzles from the corner inward.
The amount of water build-up will depend on how much you are setting it to spray. This will depend on your species, location, ect.
My free range nzzle is pointed directly at a shefflera, and the water doesnt go past the foliage really, just collects on the leaves and drops down into a tray with metal grating on top to hold the plants. If your concerned about water damage, just know that the nozzles arent going to be spraying water everywhere like a hose. Its a VERY fine mist, and the nozzles are VERY easy to direct, and when you include the regulator valve(to adjust the pressure therefore the range of the mist) I find the mistking to be very easy to control and adjust. So with a little common sense you shouldnt have an issue.
