As the title suggests, I'm curious why double insulation isn't considered an important factor when building a PC. I know most PSU's feature a third-prong for ground connection to avoid electrical shocks especially with devices with metal casing. However, given that most PC cases available in the market are made of metal, shouldn't we give more importance to double insulation for desktop PC's?
I'm asking this because I recently had a case of a PC having terrible electrical insulation. Whenever I touch the metallic parts of the chassis, I experience a tingling sensation even when the PSU's toggle switch is turned off. The tingling isn't really that painful but it's enough to keep my hands away from the chassis.
I live in a country wherein the existence of the third prong is a hit or miss. Most commercial establishments and institutions have it while most residential homes don't. Most people here also don't worry much about not having a third prong since most appliances we now have are made of plastic. Therefore, there are no other options for me but to use cheater plugs which I know is the primary reason why I have grounding issues with my chassis. However, a lot of other countries also have two-prong outlets by default (e.g. Japan) so why isn't a two-prong for PSU's isn't that common or at least have the PSU feature double insulation?
Also, if anyone could also suggest a way to workaround my problem, I'll be grateful. I also tried looking for plastic chassis but it seems like they're also not common. I can't really install a third-prong ground to my outlet since I live in an apartment.
