Wow- not to be all Poltergeist on you, but that is sort of creepy. Who knows if it is anything unusual or just a 3 year old with an active imagination?
Either way, it sounds like the parents need to try hard not to be spooked by this and let it affect the child even more. If she sees all the attention this generates, she may just do it more.
Some of it, like changing rooms or even saying silly things to her dad sound perfectly normal to me. Finding the door wide open- well, is there any way the little girl could get to the door and open it? Anyone else that could have opened it? Was it locked or just has a loose doorknob? There could be a perfectly ordinary explanation.
The same for the pile of clothes outside. Did this just happen one time? Could the little girl or someone else have tossed them out a window as a joke? Does the house creak in the wind- hence the moaning sounds? I mean, it does sound a little weird, but I wouldn't automatically assume haunted house.
That said, I dated a boy in my hometown who lived in a big old Victorian house and his whole family just assumed it was haunted from all the weird things that happened while they lived there, and how their cats acted, etc. His mom told me some very strange stuff - but nothing ever hurt anything and they just got used to it!
Have your friends go to the county records office and find out more about the house. You don't say how old it is, but if anything big ever happened there the local newspaper, county clerk's office, etc. would have records at least of who lived there, who built it and when, etc. If they seriously think its haunted, I would be curious to find out more!
