Beware of leaking ground power cable!! - This happens to my house where ground cable is leaked out as a result it transfer back the current to all electrical appliance in the house. Even if all the appliances are turned off but as long as the cable connected to the power source it still delivering electrical shock. The first electrical shock i experience was the water heater switch - before my finger could reach the switch button it already generating quite an intense shock. The second one was the electric cooker before i could hold the pot to take rice the shock was hurting. And the third one is behind the refrigerator and that was even more dangerous - as i was trying to turned off the rice cooker switch behind the refrigerator and before I could reach the switch where my hand was still in between the fridge and the switch. I could feel the strong shock and that finally lead me to professional electrician to check all the wiring problem. He discovered that some of the wires in the house was short circuit and the ground cable was leaking.
See my rice cooker generating electrical shock