If someone comes onto your property and is not wanted, you can call the police.  If your neighbor has the music too loud, you can call the police.  If someone's lights shine into your house, that is also a nuisance and what can you do?   

Any light that comes onto your property is trespass, whether it comes from a business, a neighbor or from a streetlight.  Light Trespass is so simple to fix.  In the left picture below, the Acorn Light shines into the house.  By shielding the light, no more Light Trespass.  Also, notice how much light is under the streetlight.

 

 

 

If your neighbor's lights shine into your house, print out some of the pictures from this website and go talk to them reasonably.  Or you can buy shields for Flood Lights to eliminate Trespass

http:://www.parshield.com/index.html