Never been myself but Ohio sanatoriums in general have a reputation that's hard to ignore. Waverly Hills gets all the attention but I've read accounts from investigators who say some of the lesser known ones are far more active, probably because they haven't been picked clean of energy by a thousand ghost tour groups trampling through every weekend.
What's drawing you to Briar Hill specifically? I'd be curious whether anyone has done spirit box work there. In my experience those old medical sites respond really well to direct questioning, something about the residual energy in places where people suffered for years.
Anyone got footage or audio they can share? Always better than a written account tbh.