Hi there !
( Probably can ghost that topic, I tried to replicate the issue today in the same world and wasn't able to. I made some changes in my mod list, maybe it's that... I really dont know.. I don't even remember what mods I removed lol Coming back to edit again if it happen again or if I understand what was happening ! )
I'm just starting to use Rampant, I dont fully understand what's happening, but when I install a searchlight near a forest where there is acid bitters : (Well not sure those are really called the acid bitters, but it's the small greens ones that spit acid and that spawn at fresh save.) Well those bitter's acid don't seem to start fire on it's own, nor the searchlight do on its own either, but a weird wedding occures and a big forest fire start ; Seems like the light beam is lighting the acid on fire.