Astral Projection

Out of body experience The experience of floating outside of, and in some cases, seeing one's physical body from a place outside one's body. This usually occurs spontaneously and is linked to dangerous circumstances, a dream-like state, a near-death experience, or use of psychedelic drugs. In this episode Dean tells Tessa that if they are having an out of body experience it means that they are spirits of people close to death. Other names for an out of body experience are bilocation, crisis apparitions, and fetches. – Pad of Definitions (2.01 In My Time of Dying), Official Website

Episodes

4.15 Death Takes a Holiday

Dean and Sam arrange an intentional out-of-body experience when they have psychic Pamela Barnes send them to the astral plane so that they can investigate their case. Once there, they are vulnerable to salt and iron, like ghosts. However, they also possess all the powers of normal ghosts, and they are able to see the reaper Tessa. With the help of Cole Griffith, they learn how to use their powers properly and save Tessa from Alastair, who was captured by Castiel while chasing Dean. Sam is pulled back to his body by Pamela after a demon attacks her, but Dean stays a spirit long enough to help Cole cross over with Tessa.

8.15 Man's Best Friend with Benefits

As a witch, James Frampton is capable of astral projection and uses it to spy on his rival Ed Stoltz at the police department, projecting into Sam and Dean's minds what he sees. Using astral projection, James, Sam, and Dean learn that Stoltz is building a case against James for the murders that have been happening recently and they find a clue to who is framing him: the familiar of his friend Spencer, Phillippe LeChat, is the witness against James that Stoltz is building his case on.

10.10 The Hunter Games

In order to spy on Crowley, Rowena performs a spell where she invokes the Wings of Titania. The spell allows Rowena to astral project, leaving her body at Needham Asylum and traveling to where Crowley is meeting with the Winchesters.

13.19 Funeralia

While meeting with Sam and Dean in a hotel lobby, Rowena ensures her safety by astral projecting, a fact unbeknownst to Sam and Dean until they attempt to force Rowena to leave with them.

13.20 Unfinished Business

Scouting out Michael's Fortress, Jack astral projects to confirm that Michael and his forces have abandoned it.

When confronting Loki in the penthouse of the Ophidian Hotel, Dean tries to stab him with Gabriel's wooden sword, but it phases through him when he tries to stab him, however Loki's astral projection is still capable of inflicting harm to Dean. Sam momentarily tries to shoot the illusion as well, but it completely disappears while the real Loki battles and is killed by Gabriel.