Emergency Pocket S'more Kit
This seems like it could be incredibly dangerous. If there was some fault in your wiring, that "earth" prong could become live at 120v (or 240 in some countries) or more in some situations (lightning, an upstream transfomer fault, etc).If you were to insist on doing this, I would recommend a large (like 2W) 10M resistor in line. This way, it will still dissipate any static charge but will limit current in the event something goes wrong. A better solution might be to put a seperate ground in place by installing a long, copper plated rod into the earth, far from the electrical safety ground, and use that for grounding beds, yourself, etc.
Discrete Op Amp
Don't get me wrong - I do love the project! I realise using the valves would not be practical, particularly as you're running off a single 18650 ;) I've just rebuilt a valve mantle set myself, and also a portable bluetooth speaker. It's pretty amazing to compare the technology.
Make Your Own Sensored ESC