I live in a rented house and it's electrical wiring doesn't have a ground line. I'm using 3-pin plugs with 2-pin converter. I have desktop computers, laptops, wireless routers, network switches etc all plugged into this ungrounded line. Touching any metal parts on this devices proves the current on their body. I didn't measure the current using meter but electrical testers always shows off. Can this ungrounded line cause damage to the electronic devices I mentioned?