Very little time is needed to produce the phase indicator wire from... disposable syringe (see figure). Take any suitable the dimensions of the neon lamp (for example, TH-0.2) and solder to one of her conclusions metal pin - probe of such diameter that it fit into the little pipe of the syringe. A second terminal of the lamp connect stranded wire (in isolation) with the resistor is 0.25 a resistance of 220 ohms - 1 Megohm, and the resistor - with screw, inserted into the tube, closing the larger end of the syringe. On the upper part bulb lamps you can wear a rubber centering ring. Lamp with pin insert in the syringe, and close it with a stopper.
Touching your finger to the screw, tap the pin to the details or conclusions check the electrical circuits. When you touch the probe phase wires neon the lamp begins to glow.
Author: S. Oak, Saint Petersburg