I noticed the vibrations while charging in France and Germany with my American iPhone and MBP, but just chalked it up to my universal power adapters being not 1

I noticed the vibrations while charging in France and Germany with my American iPhone and MBP, but just chalked it up to my universal power adapters being not 100% native. Reading jordwest's 60Hz comment, it seems to do with grounding. So do MBPs and iPhones purchased in Europe still experience this issue if the apartment isn't grounded properly?