Some suggestions for sand badge consideration.
Replace an outlet, light switch, or light fixture safely. Show some sort of lock out/tag out procedure & verify with a KNOWN GOOD meter that the device is OFF before replacing the device. Show the new device installed & working. This is a skill that almost everyone could use at some time or another.
Wire cutting & wire stripping. Perhaps using several different techniques & tools. It's not difficult but I've seen terribly unsafe examples. Maybe the use of wire nuts or crimped splices or a terminal block along with the fresh stripped wires.
I strongly discourage the use of electrical tape. It has a purpose but it's not the cure all prevent all miracle stuff some people try to use it for. Shrink tubing is generally much safer & easy enough for sand badge.
Securing outdoor wires so they won't chafe the insulation & cause sparks.
Eliminating those cheesy outlet expanders that allow multiple things plugged into one socket. Or too many extension cords. Or cords hidden under rugs. A good surge protector is one thing but no use asking for electrical fires.
Maybe baby proofing all outlets with the plastic cap inserts.
Showing a fire extinguisher rated for electrical fires mounted in the shop or somewhere central.
Demonstrating the use of a simple outlet tester. https://www.lowes.com/pd/Southwire-Analog-120-Volt-GFCI-Receptacle-Tester/50129726
Maybe a few ugly pix of the consequences of doing it wrong!!!
These tasks (& the battery maintenance) all emphasize the safety aspect. They also seem like logical useful starting points for the average homeowner/builder.
I would almost suggest demonstrating all the basic functions of a multimeter as part of sand badge but that can be bypassed with simpler/alternate meters that folks might already own. So DVM functions might be a better starting point for the next badge.