Well you've recently made a change by beginning to mist the cage. Rainfall can simulate a breeding response in some reptiles and amphibians.

More than likely the snake is just out and about and it only seems abnormal because ball pythons do it much less than other species so when you catch them it seems crazy.

What are you using to measure heat? When are you measuring the temps. Could be evening hits and your furnace or something kicks on raising the temps to uncomfortable levels.