Okay...
To switch the lights off, the easiest way would be to use a script.
Create a trigger with the condicion,
not (alive NameOfBulding)
On activation
[] exec "Scriptname.sqs"
Now you need to find the ID of every lightpost. You press the show ID button in the editor. You need to zoom a lot to see the id's.
Then write this in your script file...
Light1 = NearestObject ["Object xxxx",StreetLight]
Light1 switchLight "Off"
Not sure about the syntax though...
I know that I'm not very clear here, but at least it can give you some ideas to build on...
Good luck.