Nice puzzle game! :D I thought the whole idea of the ghost being able to possess objects to control them when being sufficiently close, plus all the behaviours of the items, were both really flavourful and good puzzle material!
My favorite level was level 8, it was challenging in a very interesting way.
In level 9 I was confused at first because I didn't expect one could move through objects, since the ghost doesn't move through walls and gates. Maybe I just didn't notice it before, or maybe that should be made clearer earlier? One could also consider whether preventing the ghost from passing through objects would add an interesting constraint to the game or not.