If you commute to work on the CTA, you may think you've seen some scary stuff. That's nothing compared to what you'll see on the HAUNTED 'L' Thursday through Saturday (2004). The Ghost Pirates of the Lake will invade the elevated train in celebration of Halloween, with puppets and performances from Quest Theater Ensemble. The Haunted 'L' runs Oct. 21 and Oct. 22 at 7:00 p.m., 7:25 p.m., 7:50 p.m. and 8:15 p.m.; and Oct. 23 at 11:40 p.m., 12:05 p.m., 12:55 p.m. and 1:20 p.m. The 25-minute rides are free, but are limited to four per person, and you must get tickets from the Chicago Cultural Center, 77 E. Randolph St., 312-744-3315, http://www.cityofchicago.org/specialevents