Hi loveryan
I'm not sure whether sending fan mail to the Oscars via venue will be a good idea. Since the whole Oscars ceremony only lasts a few hours, a lot of things go on behind and in front of the screen. You could send fan mail, but due to the limited time frame in which the Oscars are on, I don't think celebrities will have enough time to have their mail forwarded to them and for them to read and autograph anything you send.
Celebrities there are at the Oscars for a reason - to witness the awards ceremony and accept any awards they are honoured to receive. Fan mail is a good idea, but will be in the back of the minds of almost everyone there. The most likely way to receive an autograph at the Oscars would be to wait for the celebrity when they walk on the red carpet for an in-person signature.
Good luck! Great idea though

. You could try to send mail via the Oscars, but I think it will most likely be forwarded to the relevant celebrity agent.
nowandagain [rockon]