I'm sorry we didn't have more time to chat Swifty.
I don't think you'll get much joy from the squash courts. CITBs last (AFAIK) pronouncement in the 2000s was to acknowledge the ghost stories but refuse further comment. Now they won't talk about it at all.
Jamie Heiffer, the chair of the BN heritage project is sceptical of ghosts but he will chat about what he's heard, which isn't that much. Security have told him vague stories of the figure floating about the old runway.
As I said, a friend and I wandered onto the base complex deliberately as we wanted to be challenged by security which might have led to a discussion on ghosts. There was no one there!
I walked into the reception of the unlocked Birches and it was empty too.
Apart from the car parks behind the CITB barriers most of the parking spaces are open (though buses only run Mon-Fri) so there's nothing to stop you wandering around the southern part of the complex where the heritage centre (the old commandant's house), the squash courts and the Birches are to be found.
I did try the door handle to the squash court and the handle gave a bit. "Great! I'm in!" (The padlock was missing). But the door stopped after a cm or two and my luck was out. I was semi joking about signing a waiver about asbestosis if it meant accent. Theres also another reason why access is not allowed - there's no fire escape.
There's loads of other places to visit, most of them accessible to the public. The house in Heacham is now a holiday home and while I didn't contact the new owners, the widower of one of the Wilkes daughter's did and he was told, "it's all just stories" when he mentioned ghosts. Pure BS, I feel sorry for the family especially after the townsfolk and clergy took the piss out of them, leading to the exorcism cover story. The Rev Pott sounds like an unsympathetic loon. I mention some of his antics in my book. Sadly when George Wilkes died (about 1975ish) and Emily in 84, Pott presided over their funerals. That must have gone down well !