Weeper Warning is a written note found in The Brigmore Witches.
Keep clear of this area. We've penned the weepers inside so they can't get out, but nobody is foolish enough to go in there and put 'em out of their misery. The plague will kill them off eventually. Until then, consider this area off limits.
It can be found during The Dead Eels mission in the Drapers Ward Riverfront. The note is stuck to the left side of the large rail car parked partially inside the storage area with one or three weepers inside.