I question them easily and first on the basis of how often they venture out with crappy, noisy equipment, and then try to claim that the interpreted-noisiness of their equipment is the very phenomena they set out to find.
That is to say, many of the shows send people out with cheap, $40 voice recorders that pick up all kinds of random noise, which they then interpret as ghost-ish. They seem to prefer these cheap, noisy recorders over better quality, more expensive ones that cut out a lot of the noise and provide a better, truer idea of what sounds are actually occurring.
Which makes me think that if using better equipment makes you hear fewer ghosts, maybe the “ghosts” you are hunting are just the noisiness that better equipment cuts out.
And if ghosts wanted to make their presence known, why would their manifesting be way down in the noisiness of equipment failure, and not bigger and more obvious and pronounced enough to be clearly not noise.