AC power on front panels

I don't think there is anything intrinsically unsafe about the switch itself, which is rated for line voltage and likely UL approved. The idiocy of the IMSAI design is that the switch is connected via PC traces to solder pads at the top edge of the board where the wiring to the power supply attaches -- live line voltage exposed at a location that just invites contact while one is otherwise careful to avoid the power-supply internals. I've seen people put a few strips of electrician's tape over the pads to insulate them, though a fold of fishpaper and hot-glue might be less likely to fall off with age (??). Another piece of bad design is the bare metal fuse clip that is so close to the edge of the power supply PC board that I would be concerned about the possibility of contact with the case cover, e.g., if the case was sufficiently deformed. Another fishpaper might be a good idea there. --Bill