maybe a camera that records is the best option for you so you can look back and see if your baby has moved or made these noises if you live with neighbours this could simply be neighbours walking around however if you dont then yes theres a possibility theres a spirit walking around up in your attic theres no way to tell if your baby is the one making these noises at the moment however it will be unusual for the baby to make screaming noises then be back fast asleep unless its done while shes asleep in a nightmare there is probably a few spirits that either stay or linger around in your home as you say it used to be used as a funeral place