Yesterday as I drove past the intersection of Summit Street and St. James Avenue in Fairhope, I was intrigued by what I took to be a new addition to the stop sign, a mysterious yellow contraption on the top. This intersection is on my walking route, so today I was able to inspect it more closely. To my surprise, I realized that the stop sign was a portable one.
Google Maps’ Street View clearly shows a fixed stop sign in the same location. I suppose it must have been knocked down.
As for the odd yellow device on the top of the stop sign, here’s a closer look:
My initial thought was that it might be some form of illumination although, since there’s a streetlight at the intersection, it’s hard to see why that would be necessary. Inspection did not reveal anything resembling a light source, either.
When I got home, however, and uploaded the photo and saw the embossed “Sundowner,” I was able to google and determine that it is actually the bottom part of one of these (an “LED barricade light”):
Obviously, when the stop sign is deployed at a construction site, this caution light is required.
WalkThoughts 
This stop sign is behind a school building that most recently served as the Fairhope K-1 Center. Vandalism at the (now vacant) school has been reported; perhaps the damage to/removal of the stop sign is related.