I have seen apparitions that seemed like Demons, both under the influence of drugs, and more recently when completely straight.
I also remember as a child with a fever, I was in bed and my mom had a wall of icons, I was hallucinating from fever and calling the Icons a "Junkyard".
I often think about these moments and believe that Satan will take advantage of any weakness, but that can be any type of everyday human weakness. Even such as being drunk at a wedding, such as the one in Cana. Or the usual weaknesses of lust ,jealousy pride,etc....
There are many ways the devil finds us weak, and tries to take advantage, and we go along and end up sinning because of it. This does not mean you will end up possesed in a way needing exorcism.
We simply have to pray and acknowledge our weakness and renounce satan and praise the Lord, and God will give us the strength to prevail over further trouble.
Thus we are spared from becoming more seriously in danger from minor demonic exposure, and keep ourselves from falling deeper.
I have read books on exorcisms and what led up to the point where such drastic measures were needed, and every time the person had the ability to deny the demons, but as time wore on them they let themselves go, but they could have avoided the later need for help if they had fought the urge, and all said they knew where was the point which they gave in .
God tells us in the Gospels that we always have a way out, we often ignore it. But rarely do we allow it to go so far as to need exorcism.