You are i think mixing up neutral and earthDevice, like hair dryer, does not come with a netural wire as it is enclosed inside a plastic case. Also, most devices made, may be for example from China , may not come with the netural wire.
So what would be the best ways to made available an on/off switch outside the house and prevent people from getting a shock?
The volts in the system are generated between Live and neutral.
yes in a lot of countries, neutral is regularly bonded to earth, but that's not guaranteed.
Earth is there as a safety item,
Items that are double insulated, do not need to have earth , as there are at least two separate insulation barriers between the user and the live,