Wiring – How should I wire toe kick lighting for bathroom vanity

First of all, when you read about a "50W LED", it is certainly saying that it outputs the equivalent light of a 50W incandescent light (although that is often a exaggeration). That "50W" LED actually draws less than 10 watts. This means that it draws much less current and emits much less heat, both of which are the factors that typically limit the allowable light in a fixture.

You'd be able to replace a 50/100/150W 3-way with a lower wattage, even if staying with incandescent.

Second, unless the LED light is marked "dimmable", don't try to use it on a dimmer. You may damage the dimmer, light, or both. Even if the light is dimmable, some dimmers will not work well with a low load: a dimmer that works on a 100W light bulb may not work on an equivalent-light-output 13W LED. They make LED/CFL specific dimmers that may work better.

As for the 130V R40, that is probably a "long life" bulb. Running an incandescent at lower than rated voltage extends its life. Therefore, they make 130V bulbs to run longer on 120V. Just use LEDs rated for 120V.

As for your existing florescent lighting, I assume you're talking about the straight tube type. For a fixture that old, it's probably less efficient that newer florescent fixtures or LEDs but still much more efficient than incandescent. This is harder to replace with LEDs, just due to the area covered. There are LED tubes made to replace florescent tubes but they are still expensive and generally require re-wiring the fixture. These are most often used in commercial applications.

It sounds like you have or had knob and tube wiring that might have been converted,
which consists on a Hot and a Neutral With no Ground (which is needed for GFCI, but

sometimes use the Neutral pigtail to mickey mouse false ground,).

*You can add a ground with a wire to copper pipe from sink’s water supply or run to basement)

14-2 wire is rated at 15 amps MAX

12-2 wire is rated 20 amps MAX

If you splice or run off a 14 Gauge to a 12 Gauge you must treat it as a 14 gauge

The higher the gauge the smaller the wire weakest link being 14 while using 14 to 12

If you are rewiring the whole bath and rooms then 12 gauge is the sanest answer

12 Gauge handles 15 or 20 amperes 14 should not be more than 15 for safety reasons

(When using 12 on 20A breaker use screw terminal as opposed to tension insert)

Testing for a hot wire when there is no labeling on wire casing (sheath) use a meter on ~ AC

And use a ground from ground cold water pipe and then touch pos lead on each wire (they do sell polarity test tools also don’t always work with conversion wiring)

The 110 – 120V reading wire is the hot

Hope that answers your question.

Sincerely BEAR