Note there isn't a 'might' in that claim. I looked it up online and I got the 'might' part in my search results, well it was the word 'perhaps' which doesn't declare it the world's longest light fixture, but does suggest it's a very long light fixture.
The post office at St. John's University has a new name. President Barack Obama has signed into law a bill that designates the Collegeville Post Office in Guild Hall as the "Eugene J. McCarthy Post Office".