Tom Prigg, D McCandless Twp, will challenge Keith Rothfus this cycle in PA-12. I believe prior to this he ran as a Green Party candidate. He was at the pro-ACA townhall in Beaver last month that Rothfus wouldn't attend. He stood up and introduced himself. He's got an interesting background, but was kind of soft spoken at the townhall.
Link FYI:
https://www.tompriggforcongress.com/
He also has crowdpac and actblue fundraising pages for anyone interested in donating.