When the Red Devil is running the axes on the walls of the tunnel, it is a nod to Wes Craven's A Nightmare on Elm Street (1984).
Chanel (Emma Roberts) ridicules Grace's (Skyler Samuels) obsession with trying to figure out who the killer is, by calling her Nancy Drew. Nancy Drew is a famous female literary character known for solving mysteries. Nancy Drew (2007) was remade as a film with Emma Roberts as the titular character.
This is a 3-part Halloween Special episode, along with 1.4 Haunted House (2015) and 1.5 Pumpkin Patch (2015).
Chanel, played by Emma Roberts, derisively calls sleuthing Grace "Nancy Drew." As a young actress, Emma Roberts was the eponymous character in Nancy Drew (2007).