Can you tell me what species of bird flies over my house most nights. It's very light coloured and makes a very eerie noise! It's quite scary in fact!

I'm sorry, I doubt anyone is going to be able to identify the bird on that very sparse description! Can you get a photo or a sound recording? Or even describe it in more detail? Feel free to post again.

If it looks white from below and sounds like a banshee hissing and screaming then - if you lived near me  - I would say you may be lucky enough to have a barn owl living nearby. Some sound clips here might be a useful comparison

http://www.allaboutbirds.org/guide/Barn_Owl/sounds

I should stress this is educated guesswork not a firm ID (see MIke's point!) and barn owls may not even live where you are!