Ray Walston episode

This episode was extremely well written and had me on the edge of my seat. Seriously, if you haven't seen it, keep an eye out for the rerun. With that said, I've got to point out that I noticed an uncanny resemblance of the plot to Stephen King's 'Misery'. I looked up the dates and it looks like this ep beat the book by a few years. I mean, it's all there....the male author writing romance novels, the psycho fan obsessed with a character...Coincidence maybe, but has anyone ever heard if there were any questions surrounding the writing? I looked up the writers of this episode and that was no help at all. It's like these 2 people rolled into Hollywood, wrote this awesome script for a hit tv show, then rolled right back out of Hollywood to never be seen or heard from again. Maybe Sidney Sheldon really wrote it?