Because, statistically speaking, there’s too good of a chance of accidentally shooting a friend or family member by mistaking them for an intruder, I thought of a way to make the intruder do all the hard work for you:
It looks and feels like an ordinary rifle. It goes on a display rack in the living room, fairly close to the front (or back) door. Ammo is left nearby. The home invader comes in, sees the gun, and can’t believe his luck. He picks it up, loads it, and chambers a round. Then he finds you. You refuse to do what he says, and he gets pissed. After a little more tension, he decides to fire.
But that’s when he finds out that the magazine he loaded was just a dummy, and the gun already had a bullet in its real chamber. The butt of the rifle conceals its real barrel, which sends his shot straight into his shoulder. It’s a small, fairly weak, non-lethal shot, but it’s still enough to render his dominant arm useless and give you time to hold him down.

As a bonus, I suppose the gun could also be set up to automatically call 911 as soon as it’s removed from its display. It sends a pre-set message that will bring both police and paramedics to your house.

I mean, it WOULD work... It’s just probably too complicated to do it well.