Over the last year I have periodically noticed a strong chemical smell like burning plastic which takes my breath away, stings my throat and leaves me with a headache. Others have noticed it too although not as much as me. I assumed someone must be burning rubbish or something nearby and it was seeping in from outside. However, more recently I’ve noticed a clear pattern as to when the smell appears. Whenever I am drifting off to sleep, the precise moment I fall asleep, the smell instantly fills my nostrils and wakes me up before dissipating a few seconds later. I’ve tried this day and night, in different rooms and I get the same results. This is obviously infuriating and stops me from sleeping properly (although thankfully once I do manage to fall into a sustained deep sleep it doesn’t persist). I haven’t told anyone about it since I don’t know how to explain it without sounding crazy. It surely has to be controlled by something that can detect my brain state because simply lying down with my eyes closed doesn’t trigger it, only actual sleep triggers it. Given that there must be some serious tech behind this, it must have been tried on others who could confirm having a similar experience to this.
First of all, you have likely actual paranoia or schizophrenia and need to get treatment.
Apart from that, there could be various reasons for the smell and its timing. For example, it could be always there, but you’re used to it unless in the almost sleep state. It could also be associated with an action, like a faulty electric installation that always heats and grills plastic when you switch the light off. It could be your phones battery when you charge it in the evening. It could be funghi, chemicals or carbon monoxide causing a hallucination of a smell; or worst case scenario: You have a physical health problem that causes phantosmia, such as an infection, brain tumor, neuroblastoma, stroke, dental issues or nasal polyps.
It is extremely unlikely it is caused by a sophisticated remote or stealth sleep detecting device. Such a device is science fiction. Imagine the cost and effort to build and deploy something like this; and for what? To drive you mad? I doubt someone hates you that much to go through all that trouble.