It would be extraordinarily easy to "intercept" your own cards, if you had a willing accomplice who was willing to be dishonest & pose as a secretary, & could speak enough "theocratic jargon" to pass muster. Especially if that accomplice lived far away, preferably in another state. Quite frankly, I'm surprised it doesn't happen more often.
If you want to fade away and have the possibility to move to a far congregation for a while, I guess you can have some fun. Anyway all that information is about you, and is kept even if you don't want to (yeah, I know they put you to sign on the file that you agree that they should keep it, but you can't change your mind). If you are caught, you can say that you meet some JWs on the street and the guy said that he was the secretary and you gave him your congregations details. What can they do to you? You want out, you don't care! They should understand that people love their friends and their family and you can't just take them away because of different oppinions . Things people do for love and for fun.