Where is the setting in Nancy drews the invisible intruder?

In "The Invisible Intruder," the setting primarily takes place in the fictional town of River Heights, where Nancy Drew and her friends navigate various locations, including a mysterious old mansion. The story unfolds against the backdrop of a local mystery involving strange occurrences and an unseen presence, which adds an eerie atmosphere to the narrative. The combination of familiar and spooky locations enhances the suspense as Nancy investigates the case.