SOLVED. Children's or YA book: Kids in school are getting hypnotized by a book series. [s]

[Jessica]

I have vague memories but there was this book I really liked as a kid. There was a popular book series kids were reading and it was making people do and feel things...if I remember correctly, kids started thinking their food was worms after reading about a book involving worms, and kids start thinking their head is on fire. The main character doesn't read the books, but their little brother ends up reading them and says his head is on fire. The main character and a friend set out to find the elusive author of the books and does. Don't totally remember what happens after that. It could've been a Fear Street book perhaps but intuition tells me it wasn't?

[Rosa]

The Mysterious Matter of I. M. Fine

[Jessica]

@Rosa yup, that's it exactly. thanks!

[Rosa]

You're welcome!