Is there a way to 'find' horizontal lines?
Searching for "^g" will report pictures and horizontal lines.
You can also "select all" (Ctrl+A), click the "Select horizontal line" command of the "Horizontal line" context toolbar, then use the "Show more selections" command of the "Edit" toolbar to navigate among the selected horizontal lines.
The "Objects and special characters" section of the Reveal formatting panel of the Control Board also reports horizontal lines.
You can also "select all" (Ctrl+A), click the "Select horizontal line" command of the "Horizontal line" context toolbar, then use the "Show more selections" command of the "Edit" toolbar to navigate among the selected horizontal lines.
The "Objects and special characters" section of the Reveal formatting panel of the Control Board also reports horizontal lines.