Oh yeah thats been there forever. Its at the end of Hammerberg road where it T-junctions with 12th. Easiest way is to just take 69 to the Hammerberg exit and 12th street is right off the exit. At the intersection it will be directly across from Hammerberg Road.
https://www.google.com/maps/@42.9943099,-83.7043981,1109m/data=!3m1!1e3?entry=ttu&g_ep=EgoyMDI0MTIwOC4wIKXMDSoASAFQAw%3D%3D
No rules to it, people just paint over it whenever they want. Usually its used to memorialize someone. I guess it is some sort of pump house.