Who was a border at the house of seven gables?

The character you are likely thinking of is Clifford Pyncheon, from Nathaniel Hawthorne's novel "The House of the Seven Gables". While not explicitly called a "border," he is described as a lodger in the book, residing in the house with the Hepzibah Pyncheon and her niece, Phoebe.

Clifford is a significant character in the story, haunted by the sins of his ancestors and the legacy of the Pyncheon family. His presence in the house contributes to the atmosphere of mystery and intrigue that permeates the novel.