I have a raised deck with walkway underneath. I'm in the process of resurfacing it and I'd like the switch to the sconces above and below the deck (different switches) to also light the deck (above along the railing; below along ceiling). If I had to, on top, I could run a plug-in transformer from the outdoor outlet. I don't like this solution because it's messy and uses an outlet and I don't have the control of the indoor switch (which can eventually be connected as a smart switch with motion sensors etc).

I'm considering the following options:

  1. GIVE UP - just plug in up top, and accept the fact underneath will always be dark.
  2. TRANSFORMER OFF SCONCE? - Wire outdoor LV transformer off of sconces and run LE/LED setup off that. Per code, all connections to the transformer would have to be in the box behind the sconce. Is this even possible? per code? I've never seen this done.
  3. NEW OUTLETS. Would have to go through brick (top level) or concrete (bottom level) to tap into the indoor circuit so that I could connect a LV/LED system at each level.
  4. NEW OUTLET somewhere else - find the easiest but closest place (I assume there's some length rules) to hook up a new outlet and try and connect the transformers from both locations.

Any other suggestions. Is #2 possible? I did something similar in my bathroom (tapping into a bathroom fan connection behind a wall plate), but this is outside and off of a sconce and I've never seen this before.

top level bottom level

  • You can do #2 temporarily if it's grounded, but I agree that running a 12v wire through the window or wall would be a better way and a long-term way.
    – dandavis
    Sep 23, 2021 at 20:59
  • Why do you want to mount the transformer itself outside? Sep 24, 2021 at 0:14
  • Good point. I guess the only reason is so that I wouldn't have to go through the wall with the LV line (particularly hard on the lower level), if it comes right off of the sconce. Not to mention I'd have to think hard (or higher an electrician) on how to wire the transformer off the light switch from the inside. Plus an enclosure/access panel on inside is more noticable. That said, maybe you have solutions for some of these?
    – Joe
    Sep 24, 2021 at 2:51

1 Answer 1


There's not really a proper way to do #2. You can't just have a wire running out of the bottom of the sconce. I have seen outdoor lights that have a plug built into them, so something like that would be an option. Of course then you have an unsightly cord hanging down.

My recommendation would be to plug in a transformer where ever possible and run only the low voltage wire to the lights. Low voltage runs have little to no code restrictions so you can basically do whatever is easiest. You could even put a switch on the low voltage wire inline and mount that switch under the corner of the railing or something. You're not limited to "proper" connections or junction boxes or anything else on the low voltage side.

That also gives you flexibility to install a new outlet if needed since the only thing it would be for is the low voltage transformer and wire.

  • Listing of outdoor sconce with outlet, of course other brands/styles exist.
    – JPhi1618
    Sep 23, 2021 at 18:30
  • Thanks @JPhi1618 not ideal, but the best solution that I didn't think about that . I think if I mount a enclosure for the transformer and try and hide the cables well enough, it should be fine. You probably saved me hundreds of dollars and time dealing with a electrician trying to install another outlet. Thanks again! You're a gentleman and a scholar!
    – Joe
    Sep 24, 2021 at 2:43
  • To be clear I was referring to just getting a sconce with an outlet. Id rather not have an outlet permanently occupied or a long unsightly run of LV wire. But i could probably get a small enclosure next to the sconce to put the transformer in and run the 3-prong to the sconce and the LV wire along the railing.
    – Joe
    Sep 24, 2021 at 3:24
  • You mentioned "You can't just have a wire running out fo the bottom of the sconce" Is this a code violation? It wouldn't be a code violation to put a transformer off the knock-out of the octagon box behind the sconce right? But the issue would be 1) accessibility 2) I assume the transomer would have to be outdoor rated (not to mention same specs as the manufacturer one)?
    – Joe
    Sep 24, 2021 at 3:25
  • 1
    If someone wants to know what I did. I bought a sconce with an outlet, removed the outlet, put the transformer inside, routed the LV wire to the underside of the railing and it all worked out great. Thanks everyone!
    – Joe
    Jul 19, 2022 at 3:41

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