I'm looking to install a stair light above my stairs. I plan on using a proper box, stress clamp, and all that. The wiring will have to come from my basement, through the wall. The question I have is the best way to wire this up to power.

Ideally I would run the cable through the wall, between the studs, to the nearest wall outlet and hook it up there. The issue is this is not very close and I'd have to go through several studs; plus I am not very comfortable fishing wires through walls. It would be 100x easier to use something like an open-ended extension cord: the open end gets wired to the light, and then I run the extension cord to the outlet and simply plug it in.

What are possible pitfalls with this? I plan on securing the cord to the wall, and using the correct stress relief in the box. I'd like to get the smallest extension cord possible, as I'm going to be pulling 3 watts at most.

Related question: can I make this open-ended cord myself, or this that a bad idea? I'm confident it would work just fine, but warranty, building codes, and all that.


2 Answers 2


By definition an extension cord is a flexible cord and is covered under NEC Chapter 400. NEC 400 will tell you a flexible cord is not approved as a permanent wiring system. In the strictest interpretation of the NEC the minute you secure a flexible cord to a dwelling with just one staple or other permanent method, it becomes part of the permanent wiring system.

So NO you can't use an extension cord to connect to your light fixture as you have described.

You can only use a permanent wiring system that is approved for running in an exposed area and all of those methods and materials can be found in NEC Chapter 300.

No need to answer the related question.

Good luck.

  • I see. Would it be acceptable to use standard romex to run from the outlet along the ceiling/edge of wall to where I could drill a hole to run it behind the wall to the outlet below, assuming I encased the exposed romex in a conduit? I have to run a considerable horizontal distance to get to the nearest wall outlet, so I don't want to run horizontally behind the drywall. Jan 10, 2019 at 21:38
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    @MarkHerscher - NEC Article 334 covers NM cable. You can run NM exposed as long as it meets 334.10 (A) uses permitted and 334.15 Exposed Work. if you want to run horizontally toward a receptacle. Then if you can carefully pull of the base and drill the plate and you can run the NM behind the base and turn up at the receptacle and connect up to the receptacle. Good luck. Jan 10, 2019 at 22:50

There are several legal, safe wiring methods. Using cordage as part of the permanent wiring of a building is not one of them.

Building-rated Cables (NM, UF, Romex) inside the walls

You don't like this wiring method, so skipping.

Individual wires (THWN-2) inside conduits

First, you build the physical route for the wires. Then, you lay or pull the wires in. This is the method that will suit your inclinations.

It won't be flawless, but it'll be a heck of a lot prettier than extension cords draped about.

You can use a system such as Legrand Wiremold, however that has one weakness: it's not good at arbitrary angles. Some people think Wiremold looks the most professional, especially people who sell Wiremold.

EMT is better at that, but you'll need to buy or borrow a $20 bender. It also has a more "pipey" look.

You can also use PVC, but it will be more expensive given the short length of pipe and many boxes, and you will then need to wire a ground wire, since plastic does not conduct electricity. It's also harder to bend at arbitrary angles.

You connect four places with the piping, any route will do as long as they are in communication. Don't make a loop.

  • the power source
  • the light(s)
  • the upstairs switch
  • the downstairs switch.

You are required to have either a) switches at top and bottom of stairs, b) a motion sensor, or c) simply burn the light all the time.

With the route complete, you measure out your distances, add a foot on each end for working length, and get :

  • 1 white wire from power source to lamp (also motion sensor if equipped). Must be white or gray.

  • If 2 switches, 2 (two) yellow wires between them. These are travelers and go on the brass screws.

  • 1 black from power source, to either the first switch or the motion sensor.

  • 1 red from the second switch or the motion sensor, to the lamp.

  • if in non-metal conduit, a green connecting every device.

Wiring should be fairly obvious. I would buy these wires by the foot. However if you want to buy a roll, the black, red and yellow wires can use any color, even the same color (not white, gray or green). White wires must be white or gray. Green wires must be green or bare.

  • I think I'm likely to go this approach. There won't be a switch, so that simplifies things a lot. Thanks! Jan 10, 2019 at 22:18
  • With this approach, would I be able to use romex instead, and run the conduit from the light to above the outlet, then run the romex into the wall and down to the outlet? Jan 10, 2019 at 22:47
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    You can change wiring methods in any junction box. Also you are allowed to run Romex in conduit if it physically fits without excessive bending, but you kinda have to be a masochist. Jan 10, 2019 at 23:01

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