Once again, Ludlow Street's Nada faces a rent crisis, though this time it may be a fatal one. The venerable downtown theater incubator needs to pay up more than $18,000 in back rent by October 17, or the landlord and city marshal will boot the theater from its space. (To be replaced, no doubt, by yet another bar where young Upper West Siders can spill Cosmopolitans on themselves while letting loose loud, New Economy guffaws.) In a last-ditch effort to raise the cash, artistic directors Aaron Beall and Ian Hill have scheduled an emergency benefit for Monday, October 16. On tap: a stage version of It's a Wonderful Life, featuring members of the Drama Dept., Target Margin, Elevator Repair Service, Danse Macabre, and Gemini Collisionworks. Doors open at 7 p.m., the show is at 8:30, and a donation of any size gets you in. 167 Ludlow Street, 212-420-1466.