There's one on Paxton St by the Harrisburg Mall (East Coast Vapor). They also have a location in Camp Hill. Very small store, but
some of the employees have really good customer service. They also mix their own flavors of ejuice, if you don't mind PG.
The Blue Door Vape (Blue Door
vaping) is in Mechanicsburg, but I've not been there yet.
The
vaping Vault (the Vaping Vault PA) is on Linglestown Rd in Harrisburg. I just spotted it yesterday, and I plan to pop in at some point.
The Broad St. Market in Harrisburg as well as the Capitol City Mall both have vaping booths. Nothing super special there, but the vendors all vape in public areas, so that's pretty cool.
Hopefully that helped!