What part is this?

[JesseK]

This is safely possible via a commercial dimmer that uses a TRIAC. It basically digitally sets a timing on the output at 60 Hz minus a delta, and the delta variable is what controls the dimming. Nothing ever gets hot, there are no pots that will over load and you're not using more than the load of the light bulb in the electricity.

You can dynamically adjust the delta via a rheostat or the likes. Since this part is separate and isolated from the power supply it is safe, therefore perhaps you can figure out a wireless way to replace the rheostat.

If X10 doesn't use a TRIAC and you're sure you want wireless, you can look for an industrial-grade dimmer. TRIACs all basically work the same.