Although we cannot completely deny the existence of some mysterious things, in fact, people often scare themselves.

As far as you listening to music is concerned, it is probably due to your own psychological effects.

Maybe I didn’t think much about it when I first played the song, but then I probably thought it was already past 12:00 in the evening, and then...

The so-called "thinking" here Maybe it's just your subconscious thoughts that you don't realize. But the subconscious mind can directly reflect into the human brain, causing people to experience auditory hallucinations.

Purifier

As for the purifier issue, I don’t know what brand of purifier you are using. For example, if the smaller one like the one I use, doesn’t it automatically shut off if the water inside is used up?

Or for larger purifiers, some kind of timer mode should be commonly used. When the time is up, it will automatically turn off.

Or maybe the gate was tripped at night, the power went out, and then the power came back. The purifier probably wouldn't turn back on by itself. In summer, circuits are easily overloaded and tripping is not uncommon.