[Stentor]

Motion sensor spots. Once you get a visual, retreat to call the fuzz and get you and your dog to a defensive position so the cops don’t shoot your dog.

[unkus]

Good advice.

[Tainan]

I'll second the motion sensor spots. Get the solar powered ones. Surprisingly inexpensive.

I put them up in a yard I had when I was troubled by uninvited nocturnal visitors. Both 4-legged and the 2-legged variety. It cleared up the problem with both.

Also, I would suggest you think about speaking to this "neighbor" regarding the possible consequences of night-time trespassing. He's either up to no good or a dumba**. And either one can cause problems.

[R. Scott]

When motion sensor lights became affordable I saw them in action. I was a cab driver at the time and at night would monitor the police bands as well as our dispatcher.
I was taking a couple home late at night when a call came about a suspected burglar in the neighborhood. We watched yard lights come on, following the suspect as he ran through back yards. Police response was actually fast. They had no problem apprehending him.