Motion detecting lights work - both outside and inside.

We had a break-in about 15 years ago and my wife had a novel idea. She brought home a target that she'd used at the local gun range - silhouette of man with 48 holes in it from her 38, then hung it in the glass of the service door. She missed twice, but who's counting. We got lots of comments from people stopping by and I like to think that potential criminals (or their scouts) gave it a second thought.

Funny thing about women shooters, they tend to aim a little "low".