Switchmode AC Adapter Leakage Current
 

I have a switchmode AC adapter from a USB external hard drive and have found
leakage current lighting a neon tester placed between the DC output ground
and mains earth ground such as the case of the PC. There is a 2.2nf Y
capacitor between primary and secondary in most switchmode supplies that
have two prong AC plugs with up to 0.25mA leakage current from output ground
to mains earth ground when connected to normal AC power. Will this leakage
current through the Y capacitor be higher when plugged into a modified sine
wave UPS inverter due to abrupt voltage change between zero, positive, zero,
negative, zero, etc? Has anyone gotten a shocked from this?