Have posted this one before but will do so again.
DM was living in a house share in 60s in King Street (Covent Garden I think but could be another part of London), West End anyway. She had a really unpleasant experience when living there where she heard a man's voice in her head, saying evil and nasty things about people. Then she lost her DF's gold cross which he'd had with him in WW2. Her best male platonic friend stayed with her and gave her a Victorian silver floral cross. After a while the voices stopped and things were thought to be ok.
Years later (I was living/staying with her at this point), one of her best friends died (who'd moved to the other side of the world) and one of this friend's close friends came to visit DM, she lived the other side of England and they rarely saw each other. They were in kitchen talking and friend said to my mum "Do you remember living in King(ly?) Street? What an experience that was!". She then went on to tell my DM about an experience one night where she'd seen a woman's striped dress (Victorian looking) walk from one room to another, she was petrified but went into the next bedroom and saw the other flatmate cowering in a corner of the room also having seen this vision (apparently dress and figure walking, no face etc). They weren't sure what happened but a young policeman used to visit them (for coffee etc) and they told him what happened and he said he'd look into this for them. Turned out a woman had been murdered by a man, in that house, in late Victorian times. My DM then told her story which added up. The friend who'd died hadn't been told about this experience or if she had didn't tell her other friend.
The other event happened in 60s at some point.
DM's friends bought an old schoolhouse in Kent/Sussex countryside. DM herself once lived that way with her then DH for a year or so so she knows about the countryside.
Anyway one weekend she was offered the chance to stay there, so she drove down with her dog (Afghan Hound) and went to sleep in an upstairs bedroom. She says in the middle of the night she woke up and heard several loud bangs, and then footsteps coming up the stairs. She went out of the bedroom and took a look around (armed with something heavy) but no one was there. Went back to sleep, same bangs and footsteps resumed. After this she decided with the dog (who was freaked out) to leave that night and drove home. Afterwards her friends told her "oh yeah, we had same experiences". Which they hadn't told DM about!