What I would do immediately, just because hommie don't play with mites!
Clean out the WHOLE cage. If you are using natural hides, bake them in the oven to kill the mites, 175*F (I think) for one hour, replace substrate with paper towels, replace everything in the cage and PAM it. Be sure you read the directions fully before using PAM or any other chemicals with your snakes.
Some one else with more knowledge then I have can tell you how to treat your snake its self. I rely on the PAM, it works for millions of people....
I use plastic hides from reptilebasics.com and plastic bowls so I can wash them in hot soapy water and not worry about the mites hiding from me.
Hope this helps. Mites are not the end of the world, don't stress but don't play around.
Mike