Consider what appliance you are connecting:
There are some appliances that should *never* be grounded. In particular, that applies to toasters and anything else with exposed conductors. Consider: if you touch the heating
electrode in a toaster, and you’re not grounded, nothing will happen. If you’re slightly grounded, you’ll get a small shock;
the resistance will be too high. But if the case were grounded, and you were holding it, you’d be the perfect path to ground…