start script if specific usbdevice gets plugged in

[Husse]

This is a bit tricky
When you plug in a pen drive the number of items in /dev increases - actually by 6 for a one partition drive
I don't know which files, so I don't know if you see UUID in any
/etc/mtab is also changed - but it's not using UUID
/media is changed - again no UUID
I would suspect something happens in /proc as well
and of course there is dmesg, but no UUID there either
Time to google - but for what? Can't think of a useful search phrase...
So in essence - I could tell you how to start a script if something was plugged in into USB, but not if it is to be a specific device
Looking at dmesg I see that the size is mentioned, that might be used - trigger an event if a drive of a particular size is plugged in

[Husse]

a script if something was plugged in

but not necessarily in USB, but what else could it be.
Watch mtab - if mtab changes something is plugged in - or out
File size is probably the simplest - I haven't tried it so I'll have to leave the details to you