My neighbors are slowly going mad

I live on a pretty normal little street, at least relative to my (perhaps warped) standards of normalcy. But every once in awhile a cryptic sign will appear on one particular house's gate near the end of the block, and I'll be kerflooied if I can figure out what these cryptic messages are really about. To save me actually having to talk to my neighbors, I'd figure I'd ask y'all: what does this mean?