Shayne's lawyer fired off a letter to the famous L. Ron Hubbard shrine in Hollywood, demanding the church quit sending her bills for $1,506.35 -- claiming the bills are bogus ... and that Shayne "is not now, nor ever has been, a member of your organization or the Church of Scientology."
A Church rep claims Shayne "made a donation in 2004" -- but the check didn't clear. The rep says they'll stop sending letters to Shayne.
Best part ... Shayne's lawyer also reps her husband Nik Richie -- the guy behind TheDirty.com -- who says he's a big "Top Gun" fan and might be interested in joining the Church ... if they send him letters addressed to "Maverick."
We're guessing that's a negative, Ghost Rider.