Michael Frayn’s Noises Off is the most outrageous comedy about putting on a comedy. With rollicking wildness centering on a second-rate theatrical troupe, the “show within a show” combines classic slapstick, British naughtiness, and non-stop humor from a manic menagerie of performers rehearsing a flop with a doomed opening night. Doors slamming, mischief onstage and off, and an errant herring all figure in the plot of this comic play, with one of the cleverest set design challenges ever written for the stage.