A lot of poltergeist activity, when researched turns out to be young children. There's a child involved here. (Though in one of the incidents Holly says she was in the house alone, it is possible to be mistaken) I also note that the house appears to be quite close to Junction 26 of the M6 wiht the main exit from the motorway running right past the house so vibration may be a factor. It's also a flat so hearing footsteps is hardly surprising, and an old re purposed building so sounds of the house settling at night are to be expected.
Add in a dose of suggestion and we've got a fine old recipe for haunting reports.