Mites at shows is a very good possibility not has much from vendors also it can still happen but from the general public who is often allowed to bring their own reptile at local snake shows.
I have seen people (general public) plucking mites off their snakes and doing it very casually, like no big deal and it is because it only takes on to hitchhike on you or a newly purchased animal.
What do I do:
As a visitor
I do not touch any animal unless it is one I intend to purchase.
Once home whether I bring an animal home or not, I strip down soon as I arrive, throw my cloth in the washer, and head to the shower.
I avoid going to my snake room until the next day.
If I buy an animal well it’s like any animal purchased whether online or at a show, it goes in quarentine in a pre-treated enclosure (I use provent a mite)
Now as a vendor (which I only do once or twice a year for local exposure)
I pre-treat all my display with PAM (Provent a mite)
On the day I setup I spray PAM on my table cloth
I do not allow people to hold my animals just to hold an animal (that’s a frequent request), only if people want to buy the animal can they inspect it.
When returning home same as above cloth in the wash and shower than unpacking.
I know it sounds excessive but I never has any issue with mites in the last 15 years visiting shows.
Now for RI that is where a good general inspection and strong QT comes to play in the event a sick animal would be sold to you also it should not happen.