Violent J of Insane Clown Posse had a song about that:
I walk through houses, watch 'em watchin' TV
Talk on the phone, pay no attention to me
I like to watch pretty girls in the shower
Then they get ready, I watch 'em for hours
Some people fight, I wonder why they're together
I walk the streets, unaffected by weather
I walk through walls into bedrooms at night
Some people jump up, but I'm nowhere in sight
Maybe they sense my presence, if that the case
Why don't they hear me as I scream in their face
I try to write on the steam in the mirror
I try to touch 'em, but it's like I'm not there
Some people stop and look around the room
It gives me hope, but then they all just resume
Am I an energy, how do I channel?
How do I push a teacup right off the mantle?