I use high voltage to burn lightning-like patterns in some of my wood turnings.
I use a neon-sign transformer at about 15,000 volts. I take multiple safety precautions and approach the process with a bit of caution and respect for the danger involved.
The patterns are technically called Lichtenberg figure, and are actually the same sort of pattern that lightning makes in the sky.
I call these things “Tesla Bowls” after Nicoli Tesla, who did (among a great many other things) some pretty mad-scientist-style experiments making artificial lightning in his Colorado Springs laboratory.
I wrote a bit of a description, if you’re interested in more detail about how I do this.