Step 4: Identify the Hot/neutral Wires
There are 2 wires which power a lamp. the hot and the neutral. there may be a third which is the ground but most lamps don't have it.
Before you wire up the touch switch your gonna want to identify the hot wire (black) and the neutrals wire(white). Ground wires are green. if your power chord goes directly to the socket then you can simply look at the socket to see which is which (see photo)
Technically with a 2 prong ungrounded lamp, you can wire it either way, but I prefer to be professional about it and make sure that the wiring is proper. Once you know what your looking for, it's very easy and doesn't take any extra time.
IDENTIFY THE HOT/NEUTRAL WIRES.
Electrical code requires that the hot be identified. If the wires are colored then the hot is the black and the white is the neutral. Lamp power cords are usually single color paired wire (white, brown, etc). Look at the wire carefully. One side will have ribs on it and the other side will be smooth and will probably have markings on it. The smooth side is the hot and the ribbed side is the neutral. You can also look at the plug. the hot is the smaller prong and the neutral is the wider prong.
At the socket the hot wire connects to the bottom of the bulb and the neutral goes to the bulb screw. The hot terminal is always the darker color screw (brass) and the neutral is the lighter color (silver). this hold true with most electrical stuff like outlets, light switch's, etc.
One trick that I do is that I will put a piece of blue painters tape on the hot wire.