What version of Word are you using?
Is the line horizontal or vertical?
If it's horizontal, does it extend all the way across the page or just from
the left to the right margin?
I'm assuming that it's not a section break, column break, or page break,
since those are identified, at least in recent versions of Word. They can
also be deleted.
Does the line print?
Does the line toggle on/off when you press Ctrl+Shift+8?
If you copy that document and paste it into a new document, does the dotted
line appear in the new document?
The most frequent cause of lines suddenly appearing is the AutoFormat as You
Type feature. When that happens, you can usually get rid of them by pressing
Ctrl+Z (Undo) immediately. If you don't get rid of them immediately, then
you usually need to select the paragraph immediately before or after the
line and set borders to No Borders. It's often difficult to determine which
paragraph such a line is associated with, but it's usually the paragraph
immediately above the line. The fact that it's a dotted line, however, makes
me think that it's not an automatic border.
If you'd like, you can email me a copy of the document and I can take a
look. If so, send to herb at herbtyson dot com.
