A Westinghouse OV-20 mercury vapor fixture (1947-1952) is seen with a ladder rack on the street light bracket end for a ladder truck for when the light needed servicing. Such was rather commonplace construction on older street light poles like this one before bucket trucks became commonplace.
Added note...I believe the coned-shaped thingy in the background might have been a Civil Defense air raid siren. These were commonly seen during the "Cold War" years back then. It also could have been a tornado-alert siren (thanks for the tip, Dustin!)... given the fact that this part of the country is no stranger to tornado activity. I know of no collectors of either type of sirens.