~っぱなし (left in a state)

I'm constantly fed up with online etiquette, the lack of common sense, blah blah blah, and all that.

Was it you who left the door open last night?

You shouldn't go to sleep with the lights left on.

She left the window wide open.

But if you leave the humidifier running all night, by morning the windows are covered in condensation and dripping wet...

Don't leave the bathroom a mess.

The light was left on, you know.

Make sure you don't leave the lights on when you leave the room.