Get yourself a nice little .22 pistol/rifle (semi-auto rifle would be better due to mag restrictions and it's NR so you can just keep it in the corner with a quick combination trigger lock).
Anyone (including children) can easily handle it, shots are placed easier, and you won't go deaf ontop of already being blind in the dark.
However machetes, baseball bats, bayonets, box cutters, hammers, even tactical flashlights with pressure points (DNA collectors) can be just as effective as a gun when applied properly.
There's also pocket sand.