I noticed in my kitchen that the toast oven and the range hood had a ground fault, first by using a voltage detector pen, when getting near it the pen would activate from a distance (around 5cm without touching the case). Both of these didn't have a ground wire so I replaced the entire AC wires to put one with a ground wire that I tied to the metal chassis of both devices
The faults are "fixed", or at least gone to ground, however, I still wonder: When these devices when designed they knew both were going to be near water sources, why weren't they designed with a ground wire plug cable in the first place?
What defines when the case of a device should or should not be grounded?
What happens when a device has a fault and it's fixed like this to the ground wire in the home? Will the ground voltage go up? I'm currently sitting around 2v last time I checked (measuring neutral and GND with AC mode in a multimeter that doesn't have RMS values).