In the movie Red Lights, what exactly did the red lights mean, both within the movie title and the plot?
According to this review on The Huffington Post:
the title refers to warning signs of fraud that trained debunkers should be able to spot
This review on AXS explains this a bit more:
Red Lights follows two paranormal investigators who set out to debunk fraudulent mind readers, ghost hunters, faith healers and the like by detecting what they call 'red lights', subtle clues to the trickery behind each of these 'supernatural' occurrences.
And here's Den Of Geek:
Red Lights' title, we learn, is a reference to the practice of spotting a spiritualist huckster's tell-tale tricks.
It is also explained somewhat in this piece of dialogue:
- You know, there are two kinds of people out there with a special gift: The ones who really think they have some kind of power and the other guys... who think we can't figure them out. They're both wrong.
So what are we looking for?
Discordant notes, things that shouldn't be there.