I agree with having a dog if that is an option for you. I had two german shepherds and a two and a half pound yorkie. You might think the Yorkie was just fluff, but that was really not the case. He (Wolfie) often heard any noise before the Shepherds and allerted them, then the "big guns" took over. Wolfie couldn't do anything except let anyone know that they had been heard.
I was not home when I was robbed, and the dogs were in the garage (in an attempt to keep the dog hair to a minimum in the house). No more, if I am gone, they run loose in the house.
You could also try the candles that are either battery operated or are recharged on a base. They flicker and are very realistic and no danger so you can leave them on all night. If you wake up through the night you can easily look around and have enough light to satisfy yourself that everything is normal enough to go back to sleep. HSN or QVC carry all kinds. Some that have real wax cylinders and flicker and really do feel like the real thing. I hope they might work for you.