220V live wire-in-wall scannerThis little circuit will help you to scan the line of a 220V live wire in the wall. The FET gate is connected to a capacitive metal sensor (which is usually a simple metal plate). When you hold the sensor close to the wall, the LED will indicate the current flow around where it detects the wire. Works on 9VDC.

220V live wire-in-wall scanner
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220V live wire-in-wall scanner