Strange question about mites

I dried some bark substrate out in my shed the other day, but unbeknown to me a fox has been in there. last night found mites on the snake but dont think they are snake mites as he is not laying in water. got them all off him and put him in different tank and destroyed all the bark. but can fox mites go onto a snake and if so are they dangerous.

There are many thousands of species of mites, most of them are specific to a particular species or group. Mites that are feeding on wood or a fox are not going to affect your snake. Only snake mites affect snakes. That doesn't mean however that your snake didn't already have mites. Snake mites are very small and difficult to detect as they're usually hiding underneath your snakes scales