shadow men

I listen to Coast to Coat AM via Streamlink even though I live in Germany now. They were talking about Shadown People and they apparently dress like 1950 ad men. I found the sketch above somewhere online. What's with the fedoras? (Via Wikipedia)

Shadow people (also known as shadow men, shadow folk, or shadow beings) are said to be shadow like creatures of supernatural origin that appear as dark forms in the peripheries of people's vision and disintegrate, or move between walls, when noticed.