Switch wires to USB? Possible?

I want to mount a tablet for SmartTiles on my wall above some regular light switches.
To charge the tablet, I wanted to tap into the house wires (that are going to the light switches) and use an adapter to convert it to a USB so I can charge the tablet behind the wall.

So almost like converting your regular 120v outlet to one of those USB outlets but I need this to happen behind the wall…

Any ideas?

here is what I did… see the outlet I installed

Thanks. Yeah, I thought about that. I wanted to avoid having to go through the bottom.

The biggest thing I would worry about is meeting electrical code. if something goes wrong with that cable in wall and something bad happens such as a fire, your insurance company may tell you were to go.

400.8(5) - Flexible cords and cables are not permitted where concealed by walls, floors, or ceilings… 400.8(6) also states that this wiring method shall not be installed in raceways unless permitted by the respective raceway section.

See http://www.nfpa.org/codes-and-standards/all-codes-and-standards/list-of-codes-and-standards?mode=code&code=70

Note - I am not an electrician, nor do I do anything relating to the field. I’ve just looked into doing the same and was smacked down by a master electrician relative.

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Then these are a code violation?


From the FAQ on the page, the power cord supplied with the kit confirms to standards. Running a usb cable through a hole in the wall, which many people seem to do, does not

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Yup… There are “low voltage wiring standards” (up to 24v, I think?), which perhaps include in-wall use (certain for speaker wires, ethernet, TV cable, door bells, thermostat…) – perhaps building codes cover 5v USB somewhere… I hope!

Otherwise, the kit above is a possible solution, since you could put a 5v USB adaptor in the upper outlet.

usb is 5-7v… not gonna cause a fire or any issue.

If you short a 1.5v AA battery, it can get hot enough to start a fire. Shorted LV wires at 5v to 7v will easily do the same.