There are actually a bunch of teams in the general Harrisburg area... What kind of ball are you interested in? I know of 4 teams - one in Mechanicsburg, one in Middletown/Highspire, one in Linglestown/Grantville, and one in Dillsburg, PA.
M-burg - "Targets of Unusual Size" - http://www.tous-paintball.com
- Scenario/Woodsball - approx 10 - 15 members
M-town/H-spire - "The Glowing Goblins" - http://www.goblinspb.com
- Scenario/Woodsball - 2 full members, up to 5 part-timers.
L-town/G-ville - "The Grantville Mafia" - no website known - Unknown format - unknown total members - Considers Linglestown Paintball their home field, members often are refs there.
Dillsburg - "WPP Mercenaries" - unknown website - unknown format - unknown total members - Wanna-Play Paintball in Dillsburg, PA is their home field - consider contacting Sheldon @ WPP for more info.
I, myself, am located in Harrisburg, but I play for The Exiled Souls, a multi-state team whose home field is EMR Paintball Park, in New Milford, PA. Lots of the larger teams in PA are more wide-spread than just one city or geographic location. If you're looking to basically hookup w/ other paintballers in the Harrisburg area, check out my long-standing thread here: http://www.pbnation.com/showthread.php?t=2674779
Hope this helps!