I'm working on a project that includes chapters with different authors, and I wanted to include those authors in the table of contents. I have figured out how to treat the author by-line as a subheading in the table of contents, but when I do, I get a duplicate page number.

To remove the page number, I added:
\n 1-1 to the TOC field code. (I have also tried \n 2-2.)

When I do, the appropriate page duplicates go away, but I lose my leader dots between the entry and the page number. Using \d "." only adds individual characters, and the page numbers lose their right justification.

Is there a way to re-add the leader dots without adding duplicate page numbers?

Well, I thought I was stumped, and then I somehow managed to fix it. If you ever run into this problem yourself, here is what I did:

While in editing field codes in the table of contents, I went to Home -> Paragraph -> Tabs... and then selected the 2 ...... Leader. When I updated my ToC, it suddenly worked.

Make sure that you are changing the TOC styles.
This should happen by default, but check.
TOC Tips and Tricks by Suzanne Barnhill