Hey, I am not gonna tell you to put a (master) fuse on your electrical system
But I am gonna tell you i got a SEVERE burn(s) on my hand from a direct wired temperature gauge that grounded out while i was holding it
Building a parade float chassis, testing the temp gauge, it grounded out, the wire in my hand INSTANTLY headed up HOT!!, melted the insulation off into a drippy mess into my fist which was holding the wire. It felt like i was holding a toaster element. Melted insulation stuck in the burn. The wire's path was branded into each finger and along my thumb, if i picked up another piece of wire it matched this path perfectly
Anyway, 12v does have some safety issues, but at least not electrocution