What exactly you think are hazards in 3D printing? And low-voltage electronics? I am honestly curious to know... because I don't treat any of that as hazardous at all.

Woodworking can be hazardous when using power tools... but you can always go with hand tools only and that should be mostly risk free excluding possibility of minor cuts and bruises - but you can get these even when preparing food.

I do a lot of stuff around the house myself (renovation, making/adapting stuff, preparing my own wood for house heating, small electrical repairs, etc) and the only thing I am afraid of is the chainsaw. That thing can do significant damage even slightest mistake when being used, anything else is manageable given the usual precautions (protective gear, doublecheck that electric switches, wires, etc are not hot when working on them, etc...).