Hide under the couch.

You should probably stay nearby. That way you know right when she comes home, and maybe get her attention. You busy yourself with looking around under there. You find the usual layer of dust, an expired condom, some change, and that debit card you lost a while back. Nothing too crazy.

About an hour later the sound of keys sliding into the lock on the door breaks the silence. You quickly run over to the leg of the couch and watch the door. The knob for the top lock smoothly clicks into the unlocked position, and the door swings open. Your girlfriend then goes over to the security console and disables the system.

"One break in?" She asks as she looks at the log on the screen. She quickly walks over to her printer, watching where she steps along the way, and grabs a sheet of paper. She walks back to the front door and calls out, "Whoever you are, you have 5 minutes to come over and stand on this paper so I can find you. If you don't then you will regret it."