Christina Hartman, who just a couple of weeks switched to the PA-10 race as the DCCC favorite with a $200K campaign fund, drops out. It appears she screwed up the petition process and did not get enough valid signatures.https://twitter.com/JonathanTamari/status/978676540933369857 …
The only residency requirement is in the constitution. You have to be a resident of the state at the time you take office (or are elected, can't remember which).