The comic genius behind that (which, for anyone who doesn't know is from Always Sunny in Philadelphia) is that Charlie, being illiterate, reads "Pennsylvania" as "Pepe Sylvia".
That has been confirmed by writers via twitter to be incidental, not purposeful.
I never understood this theory. Mac’s next line after Charlie’s rant confirms that Pepe Silvia is real.
“Not only do all of these people exist, but they've been asking for their mail on a daily basis. It's all they're talking about up there.”