Where in Pennsylvania are you? Im in Indiana and there is a few rescue groups that I can give you links to.
Piggie Lovers Inc. Guinea Pig Rescue Starfish To the sea Animal Rescue Pet adoption: Want a dog or cat? Adopt a pet on Petfinder
The first two are in Latrobe and Lucernmines. I adopted one of my pigs from Piggie Lovers Inc. they are fantastic there! Check out adoption tells and if you see Ash that's one of my babies!
Hope that helps!