A shotgun would be a good choice but, whatever weapon you chose, you need to maintain proficiency and the weapon itself. Keeping it in the crawl space does neither. In general, however, you do have the right idea - be prepared to protect yourself.
"In general, however, you do have the right idea - be prepared to protect yourself."
Good point that just buying a gun is not enough. Practice and somehow coming up with a mindset that "Any stranger in my house gets killed" is important. And target identification. A friend of mine had his gun pointed at the bedroom door as it opened when his wife came in late at night returning from a trip a day early.