It is a fire light, it indicates that there is a fire pull station on that pole, rather outdated technology. I think they are incandescent but in another picture one seemed to have a CFL in it.
so what exactly is the function of the boxes? Does somebody walking by pull down the fire alarm if they see a house on fire? If that's the case, how do teenagers playing pranks not just cause lots of false alarms? I know my question isn't really related to lighting, but can somebody please inform me?
I'm not sure how false pulls could be limited, but these work like the average pull box you see in a commercial building. I think it either sounds an alarm or "calls" the fire department.
Those was used BEFORE 911 was invented! Those are still apparently alive in Boston but not only there, NYC are still using this system plus have some really old systems too! Before 911 existed....this was used!