Most likely you would smell smoke and immedately turn it off, but if a teen were using the shredder and walked away, it could overheat and put a lot of stinky smoke into a room with the possibility (very slight) of starting a fire

The shredder worked fantastic shredding 5 sheets at a time for 45 seconds when dark grey smoke started pouring out of the motor compartment.

My previous Fellowes had no smoke but died after six days due to the plastic gears being shredded