Ghost signs or “brickads” are advertisements that were painted on brick walls of buildings and very common in the decades before The Great Depression.  Here’s one for Horlacher Beer that I came across while traveling through rural Pennsylvania.  The Horlacher Brewing Company of Allentown, Pa. began in 1897, shut down during prohibition, reopened in 1933, and eventually closed in 1978.   The paint may be chipping and the weeds growing high, but ghost signs can still be found if you look for them.