If Ballroom Dancing is what you want:

The Stardust Ballroom in Bellmawr, NJ on Friday nights.
Follow the link below for more info.
http://www.stardustbellmawr.com/

The Ballroom On High in Pottstown, PA on Saturday nights.
Follow the link below for more info.
http://www.swingkat.com

If Latin Dancing is what you want:

The Stardust Ballroom in Bellmawr, NJ on Friday nights or Salsa nights on the 2nd and 4th Saturdays.
Follow the link below for more info.
http://www.stardustbellmawr.com/

If Swing Dancing is what you want:

The Philadelphia Swing Dance Society in Philadelphia, PA on Saturdays 2 times a month.
Follow the link below for more info.
http://www.swingdance.org

If Country Dancing is what you want:

Montana West in Quakertown, PA on Wednesdays and Saturdays.
Follow the link below for more info.
http://www.clubmontanawest.com