I had the same problem finding a good flare trap that wasn't an addon.
So I just made one myself using a night officer.
I just made an officer & named him(officer) & removed all his magazines & gave him all flares(10) then in a trigger I put the command: officer fire ["throw","Flare","Flare"] & set it to repeat. You can also put "this setcaptive true" in the officers init if your afraid he'll be shot before firing a flare...
Not a perfect way to do it but it worked alot better than those scripts...at least for me it did.
Hope it helps.