Quarantine it for a while. I would also move it into a small sterilite bin, maybe 6-8 quarts big with a heat pad/thermostat, paper towel substrate, and a small hide and water bowl. The plastic mouse igloos at petsmart work well, or if you have small medication boxes those work even better (like the box an asthma inhaler comes in). You could also use empty towel paper rolls or paper towel rolls. A nice small snug hide in a small enclosure will help encourage it to feed.

If all goes well you should see it roaming around looking for food after a week or two. Mice are especially palatable to ball pythons, and a hatchling should take a F/T adult mouse eagerly enough.