People have guessed camera, 5G repeater, Shot Spotter, photovoltaic cell, but I cannot get a Google Image match to any of those things. I am most interested in what the thing is hanging down.
https://imgur.com/j397nUW
Not the best photo for sure, but thing hanging down thingie does not look like a microphone for zeroing in on shots. And it’s in a very upclass nieghborhood with little traffic.
Hard to tell from the picture, but are you sure that the dangly bit is a part of the box thing? My guess, from the picture, would be that it was something someone threw up there for stupid reasons, like the shoes you sometimes see hanging from power lines.
Yes, it appears to be plugged into the box. I’ll try for a better pic manana.
I have one on the light pole by my house.
I think it’s something called a Rapid Response Radio Relay Signal Extender. Or something similar.
I think it’s used to boast the communications signal for police, firefighters, medical, etc.
My house is in a low valley sort of area so this is what it may be used for.
Update: I found this on the web. Might be true:
They’re for wireless meter reading (utilities).
Looks like an AMR (Automatic Meter Reader), the wikipedia page has the basics Automatic meter reading - Wikipedia. Here’s some images that look similar from an electric utility’s web page: AMI Project | Powder River Energy Corporation.
New pic, does this help, meter reader sounds pretty good at this point
There’s a good forum at reddit devoted to questions like this:
@chappachula
Funny you mention that, my son and I were cleaning out some boxes at my late parent’s house and came across a bunch of oddly shaped clear glass bowls.
I had no idea what they were and couldn’t remember my parents ever using them. He’s a big Reddit reader and told me about that Reddit forum.
He posted a couple pictures and within two hours somebody identified them as shrimp cocktail bowls [missing their decorative bases] and supplied corroborating pictures out of some old catalog.
I’m a believer . 
The “thing hanging down” is the power cord.
This unit (as well as all the ones in our neighborhood) have been disconnected and just left in place.