Halloween starts a wee bit early -- tomorrow night at 9 p.m. -- as WWDC-FM (101.1) parties at the Pavilion at the Old Post Office. On Sunday WKYS-FM (93.9) will cohost a costume party at the Classics III night spot in Camp Springs. Proceeds go to UNICEF. Also on Sunday, WPFW-FM (89.3) is holding a costume ball with the Sun Ra Arkestra at the Pavilion at 8 p.m. On the nutty night's eve, WXTR-FM (104.1) plans a costume dance at Champions, starting at 9. Proceeds go to the March of Dimes. Also on Tuesday, WTOP-AM (1500) and WTKS-FM (102.3) are cosponsoring, with some help from WEZR-FM (106.7) and WRQX-FM (107.3), an all-day "Alley Cat" party for the Food for Christmas fund at Rumors, 19th and M streets NW. The cast of "Cats" is expected at 11 p.m.

Finally, on Halloween night, the ghosts at the Pavilion will rock with WHUR-FM (96.3) and raise money for Project Harvest, an annual food drive. The party starts at 8. In Georgetown, WMAL-AM (630) will broadcast from Cafe Broadway beginning at 9. WRQX-FM (107.3) will party from the Bayou, and switch to other bars waving Q-107 banners and participating in Bud Light Fright Night.