So, Lynnafred and I were in Ocean State Job Lot, and they had a huge display of these hand-held bug zappers. You put two AA-sized batteries in the handle and press a small button as you swing it at flying insects...and ZAP! Thanks to the offset metal grids and the magic of a transformer between the batteries and the grid, a 3000-volt pop makes a loud electric crackle sound and a bright blue spark as the doomed insect gets sent off to Critter Hell.
When these first came out a few years ago, I was a bit skeptical about them, but it turns out that they work pretty well both indoors (we get pantry moths every now and then) and out.
But it turns out that they don't work at all at the purpose for which we bought them. We wanted to play electric tag with them, running around in the yard, swatting each other and delivering a mild shock every time. We thought that would be hilarious, but it turns out that the electric grids are separated by a permanent and non-removable spacer which was very likely designed into it specifically to prevent the shenanigans we were hoping to have.