Good idea that doesn’t look terrible and works great, go to lowes and get painters plastic, it’s about 8 dollars for a 10’x10’ roll, so if you don’t like the first time you have plenty of material to try again until it looks the way you want it, attach it to three walls of your enclosure (side+side+back) with either zip ties or twist ties, if using zip ties get the smallest ones possible so you don’t destroy the screen mesh, pull it taught and it actually looks really good. Start misting more often and boom. I did this and it took my humidity from the 30% range to the 50%-60% range