Mustafa Gatollari is one of the investigators on the TV show "Ghost Hunters" and host/producer of the series "Haunted Discoveries." While he writes that "there are too many people who've had too many strange experiences to discount the pursuit of paranormal research as a pastime for deluded hobbyists," he doesn't take kindly to TV fakery of evidence suggesting ghostly activity. For example, there's the oft-cited claim that weird occurrences are sometimes tied to aberrations in electromagnetic frequencies (EMF) measured by an electronic instrument. Thing is, the radio signals from walkie-talkies, a common tool wielded by TV ghostbusters, are known to mess with analog EMF meters. And that's just one of the tricks of the trade, Gatollari explains in the The Independent:
Let's take another popular ghost-hunting "tech" trope: flashlight communication. The technique behind this works as follows:Get yourself a twist on/off flashlight and "split the difference" so that the device teeters in between being fully engaged and not. You want to loosen it just enough so that if you tap the flashlight, it will flicker on.
Now set the flashlight down and begin your line of questioning, or invite entities to come and touch the device in order to communicate with you. The theory behind this trope is that the electromagnetic energy from the entities "touching" the flashlight will create enough juice to connect the bulb to its power source, resulting in a beam of affirmation.
Many investigative programs will stitch together video snippets of this "communication" to make it seem like the flashlight is going off after questions are being asked.