Heck, I don't need scientific proof! I have experienced a few ghost's in my lifetime and as a matter of fact we have a couple in the house I live in right now. One of them we think is a cat.
When we go to bed and start to drift off, there's this feeling we get when a cat is pawwing the blankets. But when you go to look, there's no freakin cat there! Happens all the time..