The digital electric pen has the function of measuring the voltage value, which is normally divided into 12 36 55 110 220 files.
If only 12 is displayed, it means that the voltage you are measuring is about 12V. If all these numbers are displayed, take the maximum value on the far right, which is 220V. It means that the voltage you are measuring should be around 220V. If it feels numb It should be the cause of leakage current. Does the air switch at home have leakage protection function? Is the water heater well protected and grounded? It may also be because the neutral and live wires are reversed. The normal switch should control the live wire, but if the live wire and the neutral wire are reversed, the switch only controls the neutral wire, so there will be leakage current. Find an electrician to check it, otherwise This is very dangerous, no matter how safe the use of electricity is the most important!
