Yeah, they make devices like this for stage magicians, that you can simply buy online. For example: https://illuminati-magic.com/products/thumper https://illum

Yeah, they make devices like this for stage magicians, that you can simply buy online. For example: https://illuminati-magic.com/products/thumper https://illuminati-magic.com/products/thumper Some of them seem small enough that they won't trigger a metal detector. Currently they don't constantly scan the playing hall for wireless activity, which is what you'd need to detect this in use. I bet they start scanning for wireless transmissions soon, though.