Every paragraph in a document has a style, such as Normal, or Heading 1.
The TOC includes all paragraphs with specific styles. The "extra" text
you're seeing may have a Heading 1 or Heading 2 style applied by mistake.
It can have a heading style applied but still look right if someone applies
manual formatting to change the look.
Make sure the "bad" heading is in a separate paragraph of its own. You have
to show the nonprinting characters to see that paragraph marks. Make sure the
"extra" text paragraphs don't have a Heading style applied to them. Select
the paragraphs and apply a different style if you need to. Use the Style list
to do that.
Bear