An unfortunate fact of life is that most apartments in NYC are overpriced rentals, which makes any kind of hard wiring difficult. If you’re in a situation like this, you can use this video to guide you in a DIY installation. Why waste hundreds of dollars calling an electrician?
There are usually 3 wires involved with the light source.
Positive: The “hot-wire” isenclosed in a black cover. France and Son’s light fixtures will have an “L” insignia to mark the positive. This is the wire responsible for providing the charge to the fixture.
Neutral: This will have a silver, or white cover, and an “N” to mark the neutral distinction. This returns the charge back to the source, and acts as a continuation of the circuitry.
Ground: This has no cover, and will appear as an exposed copper wire. This handles the excess electricity, and grounds it to the earth, or an accessible metal discharge.
When installing a wall light, or a pendant, find the appropriate electrical box that matches its shape. It will either be a circle, rectangle, or a square, and you can find them at Lowe’s, Home Depot, or any nearby hardware store.
The light you're installing will have a matching set of wires. So, the next step, is to twist the exposed parts of the neutral/white wires from the ceiling, and the ones from the fixture together, clockwise, then screw the cap onto the ends. Repeat the process with the hot wires. Then, loop the exposed wire around a screw inside the electrical box for grounding.
If all goes correctly: “Let there be light!”
Source: Apartment Therapy