Bad news, everyone - Ghost Hunters isn't real. That doesn't mean it's not an enjoyable ghost hunting show, nor that you shouldn't watch it. But it does mean that, if you consider the evidence (something certain investigators aren't always inclined to do), you'd see all the reasons why Ghost Hunters is fake. It's spooky entertainment with a dash of scientific flair, but it's journeyed so far from its more skeptical roots that it's hard, not to mention inadvisable, to take it as a serious inquiry into the paranormal.
Though some of Ghost Hunters might use real investigative techniques, the TV show is all about the spectacle. How Ghost Hunters tricks viewers is a mixture of scientific babble, playing with expectations, and including just enough mystery to keep fans on their toes. The show may have started as a serious-minded look into real-life ghost stories, but it's moved pretty far away from that and into the realm of thrilling "reality" TV. Even if the science isn't there, how Ghost Hunters fakes evidence is nearly as interesting as the few seemingly legitimate snippets of EVPs and paranormal activity they capture.
Ghost Hunters is good TV. Good TV is entertaining. And if the ghosts aren't appearing, the show isn't entertaining. Claims that the show is faked have plagued Ghost Hunters for some time, but when former case manager Donna Lacroix left the show, she hinted, but did not confirm, that a staging crew was part of filming. In this case, a staging crew would be tasked with setting up incidents and situations for the cast to encounter, such as strange noises, smells, or other intangible effects.
While viewers don't know for certain that those things are happening, that they're questioned by former cast members speaks volumes to the veracity of the narrative that Ghost Hunters is trying to sell.
Ghost Hunters' distinctive night vision is all part of the experience, but when you really stop to think about it, it doesn't make a whole lot of sense. Ghosts are always associated with nighttime, despite there being no real reason they shouldn't be spooking the living all day long. But night makes a convenient cover for camera tricks and suggestion rather than concrete evidence. Flashlights do strange things to shadows and silhouettes, and people are naturally predisposed to seeing things that aren't there in the dark. It's all part of the atmosphere, but it's also a convenient way to show something by showing nothing at all.
The Ghost Hunters crew has a few spirit communication tricks up their sleeves, but the flashlight bit is one of the easiest to replicate without expensive equipment. As the story goes, you simply unscrew your flashlight slightly and ask questions, and the spirits can turn the light on and off to answer.
But the explanation is less that ghosts are talking to you and more that heat expansion and contraction are making your light blink on and off. A flashlight's bulb generates heat, warming the reflector and making it expand. When you switch the flashlight off, the reflector cools and contracts. If you unscrew the flashlight a tiny bit, that cycle of expansion and contraction will make the light flicker on and off, as inner pieces briefly make contact and light the bulb.
It requires no interference on the part of the investigators, no post-production, and looks pretty creepy, making it a perfect fit for selling paranormal activity to viewers.
EMF readers are a major tool of paranormal investigators like the Ghost Hunters cast. By reading electromagnetic fields, investigators say they can detect ghosts through anomalous readings - a spike in your reading when not near an electrical device may indicate a ghost.
Unfortunately, this mainstay of the ghost hunting toolkit is notoriously prone to malfunction. Even moving an EMF reader too fast can set it off, and there's no real conclusive evidence that electromagnetic fluctuations indicate paranormal activity. If you throw out even half of Ghost Hunters evidence that involves an EMF reading as a error, that doesn't leave much evidence.