Like the previous advice, see a doctor before the situation drives you nuts and you do something you regret.
I have a friend who has schizophrenia who is nuts about ufos. He has described voices and people talking to him like that. He's on heavy antipsychotics and i have to remind him of what is real and what is not, sometimes he is way out there, but i make him think rationally. My father had similar visual symptoms after being prescribed morphine after his heartsurgery, i had to talk him into being rational and dismissing what looks like to be there vs what normally isn't there. Same thing with the sounds he did hear. He was rational and listened to me, even went so far and put his hands into the illusions and saw that it passed through.
Second of all no such agency in the world would bother implant something in anyones head to "communicate" with you or anyone else, that would be a waste of money (stuff like that would be really EXPENSIVE) and time since the could just call, email or send a letter. This is only an indicator of your brain acting like a crashing computer, that should make you worried and head towards a doctor really soon.
Think of how you were earlier, why did this change just now? Hearing voices in your head is not normal. Go with the rational thought like i described above and visit a doctor.
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"It is far better to grasp the Universe as it really is than to persist in delusion, however satisfying and reassuring" (Carl Sagan)