From The TimeSplitters Wiki

Ghost gun
Ammo	1500/1500
Fire Rate bullets per sec/cartridge time	How many bullets it fires per second (Example: 2bps)
Reload Time	Does not need to reload
Damage (per Single Shot) Head/Body/Leg	?/?/?
Type	Other
Zoom	None
Primary Fire	Fires long beam
Secondary Fire	Same as primary.
Games	TS:FP

The Ghostgun only appears in TimeSplitters Future Perfect. It is used to fight ghost, suck up their life. Same use in mutiplayer. The ghostgun will suck up the opponet's life and give it to you. It shoots out a beam of energy, like the electrictool. It does have ammo and it doesn't overheat. When holding it out, your screen changes and you see everyone as a bright blur and see ghost like normal people.