I am adding some authors to the list. Amazon doesn't have a "gothic romance" category, so it's difficult -- at least for me -- to find the specific type of book I'm looking for. There are plenty of haunted house books under Religion and Spirituality. Paranormal Romance doesn't quite encompass the real-world-but-with-maybe-or-maybe-not-ghosts type of story either. So as I find new authors/books, I will make a new post as well as add to the original list.
Elizabeth Meyette -
The Cavanaugh House and a sequel
Buried Secrets. Her other titles look like straight historical romance, but may have Gothic elements, too.