|Specifics: This is for Ghostbusters International|
The Muon Trap, or just the Ghost Trap is one of the tools used in capturing ghosts.
The Trap is a sealed container that allowed the Ghostbusters to transport the spirits to the Containment Unit, where they would be released into the grid. It is unclear what happens to the trap once placed inside the grid, though some have theorized that when a captured ghost is put into the Containment Unit, the entity is pumped out of the trap cartridge so it can be used again.
Once a trap has captured a ghost and has closed, it cannot be re-opened without releasing the ghost contained within. For this reason, the Ghostbusters must each carry several traps. They must dispose of a trap once it is used.
In the video games, traps were often absent. Some games had the player getting a ghost into the trap in order to catch it and some had no traps and simply had the ghosts destroyed by a blast from the proton pack.
In Ghostbusters: The Video Game, the player is able to use a traps to capture ghosts and confine it indefinitely after the ghost is trapped. The trap can also hold many ghosts without getting too full. Some ghosts in the game simply dissipate after long enough exposure to the Proton Stream or other weapons.
Secondary Canon HistoryEdit
Ghost Trap in the Animated SeriesEdit
At first glance the Traps in the Real Ghostbusters, look like they work the same way, but they actually performed some different functions and have different characteristics(though some of these functions were present in the second movie, such as the trap being capable of capturing multiple ghosts at one time). The Containment Unit is also used differently. The animated traps are capable of "sucking a ghost into itself the entire time it is open, not just as it is closing (as with the original movie traps).
Banished by Koza'Rai, the Ghostbusters came up with their own designs for various equipment such as the Trap. While Peter's most closely resembled the original, Ray's looked to be modified from a chest, and those used by Janine's Ghostbusters Versailles were created by Leonardo da Vinci.
An avatar of Britt stole a Trap from the Firehouse basement and used it to capture and temporarily store a portion of Gozer's essence. Several Traps were used to capture the Megaspook but it approved too powerful and melted them all as it escaped.
During an encounter with Chi-You at the Madison Square Garden, it was discovered he could not be trapped before first severing the tethers he had to his thralls.  The Trap holding Chi-You was dumped in the Turtles' dimension, 4.2 light years from Earth. For the Poveglia case, Ray stored the Poveglian Artifact in the back up Trap because it was the only thing on hand capable of containing the psychokinetic energy the artifact was drenched in.
Ghostbusters: Sanctum of SlimeEdit
The Ghostbusters continue to use traps to capture ghosts but are exhausted. They hire a junior team and equip them with new Proton Packs. The capabilities of these Packs reduce the need for the traps. The junior team only uses them once they've weakened a controlling entity such as the Electroshock Construct or Slime Golem. One clear change in the traps is the lack of a cord, which suggest that they run by remote control of some kind.
Design and UseEdit
However, it's believed that if you look in the trap for too long, you'll go blind.
Also, some have speculated that if you look into a ghost trap, the trap will suck out and imprison your soul. This idea was used in the fan film Return of the Ghostbusters.
Capturing a ghost occurs in three steps:
1) Zap 'em - Fire a Proton Stream at the ghost until they lose sufficient P.K.E.
2) Cap 'em - Activate a Capture Stream holding the ghost in place.
3) Trap 'em - Activate the trap and move the ghost to the storage facility.
The trap differs greatly in Ghostbusters: The Video Game compared to the films. It does not differ in appearance, but in behavior. For example, in the films you would need to have someone push down a button, which is linked to the trap, with their foot, and the ghost is sucked in automatically. However, in the video game the trap had replaced this "button" with a red beacon signal coming from the trap itself that, when a ghost comes into contact with it, opens and slowly sucks the ghost in. However, the Ghostbusters must use the Capture Stream to keep the ghost in the containment cone the trap releases, thus "forcing" them in. This is not how the trap reacted in the films. Perhaps it is due to the fact that, since that game is set in 1991, the ghosts have grown much more powerful, thus the trap needing the help of the Capture Stream. However, this would not explain how Slimer is able to resist the containment cone just as the other ghosts because he was seen getting sucked in automatically in the first film. In fact, Ray had even said, "Turn off your streams as soon as I close the trap."
Another explanation could be that the Psi Energy Pulse seen in the beginning of the game had given every ghost in New York greater strength, including Slimer. This would make sense since Slimer was able to break free of the Paranormal Containment Research Tank after the pulse as he was unable to before. Either way, the trap will contain a ghost indefinitely until it is transferred to the Containment Unit.
The Industrial Light and Magic animation department also expanded on the Trap and its interaction with ghosts. Instead of just having the ghosts disappear into the Trap, the team animated the ghosts coming apart and added comets and lightning to the inside of the trap cone field. Mike Lessa devised a staggered effect where Nunzio was sucked into the Trap head first and his shoes would be left behind for a few seconds. Dennis Muren suggest Tony Scoleri's eyes to be left behind for an instant. 
- According to Drew Haworth, Creative Director of Ghostbusters: The Video Game, there were discussions of Traps that players could plant like trip mines. Once set, it was like a 'super bomb' that pulled everything in the room including physical objects. 
- In the Ghostbusters: Mass Hysteria hard cover collection, different views of the Trap are explored on
- The front cover has a bird's eye view of a closed Trap
- The interior cover is from the perspective of looking up at the opening of a Trap from the inside
- Page 1 is looking into the Trap while not in use
- Pages 2 and 3 show a partially disassembled Trap on top a Trap schematic
- Page 464 shows a Trap's circuit board
- The interior back cover shows the entirety of a Trap schematic
- The back cover is the underside of a Trap
Secondary Canon AppearancesEdit
- 88MPH Studios
- Ghost Busted (manga)
- Chapter 1
- Chapter 3
- Chapter 5
- IDW Comics
- "The Other Side 1"
- "The Other Side 4"
- "Displaced Aggression 1"
- "Displaced Aggression 2"
- "Displaced Aggression 4"
- "Past, Present, and Future"
- "Tainted Love"
- "What in Samhain Just Happened?"
- "Ghostbusters: Infestation 1"
- "Ghostbusters: Infestation 2"
- Volume 1
- Volume 2
- Teenage Mutant Ninja Turtles Ghostbusters
- Ghostbusters Get Real
- Ghostbusters Annual 2015
- "Bait Date"
- "No Sale"
- "World of the Psychic"
- Volume 3
- "Ghostbusters: Times Scare!"
- The X-Files: Conspiracy: Ghostbusters
- Ghostbusters: Deviations
- Ghostbusters: Sanctum of Slime
- ↑ Ray Stantz (2014). IDW Comics- "Teenage Mutant Ninja Turtles/Ghostbusters Issue #3" (2014) (Comic p.5). Ray says: "He should've been sucked right into the trap. There's no way he could fight it unless--unless he's more directly connected to his thralls than we thought."
- ↑ Eisenberg, Adam (November 1989). Ghostbusters Revisited, Cinefex magazine #40, page 20. Cinefex, USA.
- ↑ Reddit AMA "AMA with the developers of 2009's Ghostbusters: The Video Game!" 7/16/16 Drew Haworth says: "There was a lot of discussion about having traps that you could stick, like trip mines. You could stick them on ceilings or on walls. There was a trap that once you set it, it was like a super bomb. It would pull everything in, everything in the room, into it, including physical objects ."