I met only one ghost in my two visits
Second time around I was not too happy about being there...I didn't go inside
It is an amazing house. If you ever get the chance to go there you can feel history happening...it's a very lovely house. Well worth a visit...barring ghosts 
mab
Hi Mab
You are quite right about the Hall's atmosphere - it is like stepping back in time. It feels, smells and looks so old and when I sat in the archive room, I did hear lots of creaks and groans, not surprising when you think how old the house is and how many planes fly over it in take off every day! My own house rattles from them sometimes!
I also heard the bells ringing downstairs as if calling the servants to attend their mistress but the guides told me this happens when a mouse runs along the top of them!
If anyone of you are able to visit, please do because it is well worth it.
Lynne