If there is condenstion on the walls of the enclosure, then the humidity is probably high. I had thought that maybe your humidity gauge was malfunctioning (it can easily happen with digitals if condensation forms where the humidity is recorded). What are you using as a heat source? Do you have any of the screen top covered? What is the tempature of your room and the enclosure? With an enclosure that has newspaper substrate and a screen top.....I can't see the humidity increasing unless water is entering the enclosure someway. What size water bowl do you have? Does the snake like to 'spill' its water? Other than the water bowl is there something else that is supplying water in the enclosure? Where is the enclosure located in the room? Do air condition vents blow air in its direction? What are all the contents of the enclosure?
Basically, with all these questions i am making a 'checklist' of things that can be making the enclosure so humid. I usually ask myself all of these questions when I am setting up an enclosure and trying to get the temp and humidity situated.