Come summer, the Massachusetts Berkshires are always a hotbed of cultural activity (music at Tanglewood, dance at Jacob's Pillow), and the Berkshire Theatre Festival — one of the area's oldest arts organizations, having just celebrated its 80th birthday — is doing its part with some provocative offerings. BTF's Main Stage, originally designed by architect Stanford White back in 1888, is showing a new adaptation of Ghosts, that Ibsen stew of repressed passions and sins of the father — and the mother — visited on the child, played here by Randy Harrison (a BTF regular, but most recognizable as the cute blond artist Justin on Showtime's Queer as Folk). The much younger, more intimate Unicorn Theatre presents Sick, a contemporary dark comedy about a mother who, post 9/11, strives to protect her kids by cocooning them in their NYC apartment. Tickets & info: 413-298-5576