when ever you purchase a used machine- regardless of age you should before plugging it in check the condition of the cord...machines which have been stored (sometimes in barns & garages- but even in the house) can have weather checking- can be gnawed on by rodents---any number of things.
any used electrical item can have the same issues-
before plugging anything in check the cord-
if it is in good condition the chance of getting a shock is pretty slim.