Nowadays there are non contact voltage testers. Looks like a plastic pen and usually beeps/flashes etc when close to a live circuit. There are fairly cheap ones that work just as well as any A brand. Saved my bacon more then once when you thought stuff was off/disconnected and somehow it was creatively wired. Hot grounds, anyone?
It really depends on the amperage coming over the circuit. Volts times amps is watts, usually limited by breaker. If you’re part of the circuit and there’s a large resistor in front causing the device to only draw a few milliamp then yeah, minor tingle. If you’re directly on the main with a say 20A breaker then it’ll be heck of a shock / arc when the circuit is shorted.
I bought a regular pancake compressor for that, with a plug. Once full you can just unplug and fill tires with the tank pressure. I bought it specifically for inflating tires, however I’ve used it for many cleaning jobs as well. Paid itself back several times over now. I’ve seen 12V mobile versions that differ greatly in construction. Look for something that’s heavier then most I’d say.