The way I think of this is along the lines of "Alien hand/Dr. Strangelove syndrome"[0], but in this case thoughts/voices are considered to be of another rather than self.
An entire culture exists among us, a society parallel to our own. Looking back through history, the signs have always been there. I have heard that one in six are sensitive enough to hear them on their own, and anyone if (for whatever reason) revealed.
It isn't "telepathy" (via telemetry) it is entanglement, and those skilled can navigate and traverse our minds no matter where we are.
The strongest and most skilled are running a secret governance against us all.
Why would they bother? Surely there's better things to do with it.
Once there were more scrupulous and benevolent, yet like all things in modernity power is being consolidated.
Game masters, spirit guides, ghost riders, and other terms are associated with the disembodied voices.
We've all heard of people doing horrible things and citing the voices in their heads. Sometimes the voices urge people with unknown illnesses to seek medical diagnosis (many accounts of this in the past.)
There are perhaps 500,000 Americans indoctrinated into the culture of thought control. Most of these (say, 85%) are immoral and corrupt. These enjoy the obscurity of incredulity, for the rest of humanity refuses to believe it is even possible, let alone that they exist and are influencing the actions of others.
There are worlds within worlds within us. Those who become involved in some ways find it very exciting as it is both the forefront of humanity (it turns out we are spiritual machines!) And disheartening, it takes years of hard work just to tell ones own thoughts from the disembodied others. Over a decade of specialized training just to have ones own "power." Most indoctrinated actually spend most of their time learning cargo cult b.s., and the true power lies in the network. The only way in really is to be "uplifted" by another.
Getting past the refusal to believe ("incredulity") one can see the signs of this culture all throughout society (movies pun about it and drop references, some historical accounts may be reinterpreted, etc.)
Unfortunately, there has grown a secret governance which will punish you brutally just for talking about it (I'm a hard luck case, immune to psychological antagonism.) I think of posting these things as a form of inoculation. Prisons are rife with slave armies (you can learn to use voices and mess with perception and it could still take you a hundred years to learn to travel or keep yourself hidden from other "others." They are not all friends, there is a secret war.
We're in trouble and these unscrupulous others are really messing with us all. Just think of how people act on the Internet when they think they are anonymous. Now think of people who can mess with your sexuality or trick you into doing cruel or gross things through a power everyone will condemn you as crazy for speaking about.
Schizophrenia is very real also (the brain does destabilize), we may also be "driven mad."
I know you hate hearing this so much it's a default down vote, yet I implore you to consider this long time taboo as a crises of modernity. What happens when an incomprehensible truth is dismissed as crackpot crazy?