My own personal experience of oddness in new House is a little bit second hand. Because it wasn't actually MY new house. It was my Girlfriend's (Now Wife).
Back in the early 2000s my Wife moved down from Merseyside to Kenilworth, Warwickshire, my hometown, to be closer to me. We'd been together 5 or 6 years by that point, having met at University.
She sstayed with me and my Parents for a few weeks when she first came down, while house hunting, adamant that she wanted to rent on her own first before we found a place together. I was temping at the time, so realistically couldn't really commit to a place anyway.
After several weeks of searching for decent rental houses (And not finding any) we found an advert in the local paper for a House Share with 2 others on Castle Hill, the long row of olde worldy terraced housing on the road which slopes down to where Keniworth Castle stands. A great location. Two pubs nearby, a tea rooms, and Chinese takeaway and three more pubs up the hill.
In those post-student pre-career days those were the things which mattered.
The house itself turned out to actually have been TWO houses which had been knocked through into one, in the middle of the terrace, and owned by a crazy little Austrian lady, who lived a fair distance away. They were linked by a downstairs door in the living room of the first house. It was actually a really good conversion.
My wife met the two other Housemates we'll call her 'J' (An occupational therapist at Warwick Hospital) and him 'M' a pilot for the local Air Ambulance. They were nice people and the room available was effectively the whole top floor of one of the original houses for a ver reasonable rent. So my Wife took it.
As it turned out the crazy Austrian lady was a real pain of a Landlady. A lot of the fittings in the house had a tendancy to break, and rather than get somebody else to fix them she would always come over and try to fix it herself. Badly. Often with her dog. And her incontinent mother. At all times of day and night. It was a nightmare...
But that's me digressing...
As I say, the houses here were old. Oak beam ceilings, white thick plaster walls. It got cold a lot, and this was winter/spring. But despite all that it wasn't really creepy. More... homely.
Given that there were two other tennants, my wife, and frequently ME in the house, there was quite a bit of coming and going... going on.
It wasn't uncommon to find another person in a room you didn't expect them to be. J in particular was very quite, and liked sitting in the living or dining room quietly reading. And of course access to all of the individually rented rooms was only possible through climbing the stairs at the back of the second house. The front door was in the first house. So in order to get there you had to walk through the living room, through the partition door into the second house dining room (Which had only a small partition from the kitchen too) and on towards the stairs. If you were sitting or standing in any of those rooms you'd see the person coming through, and they or you would say 'Hello'.
It was not uncommon.
What was uncommon was when we started saying 'Hello,' only to find that there wasn't actually anybody there. We could swear we'd seen or heard somebody, but on closer inspection found nobody there.
Downstairs was not well lit. The artificial lighting was very dim, and so both my wife and I passed off two or three occasiions where we had thought we'd seen somebody walk through, while we were preparing food in the kitchen, as a trick of the light on a dark winter's night...
That was until J mentioned that she'd seen something too. Prefixing her introduction one Saturday afternoon with 'Before I say this, I know this is going to sound crazy...' she explained to us that the previous evening she had been sure that somebody had walked behind her whilst she was reading in dining room. But when she glanced up nobody was there. In fact nobody else was home, at all. She'd thought it was my wife and said 'Hello'. She was a cheery woman, and not prone to believing in such silly things, but it had been nagging at her all day.
We both told her that actually we'd felt/experienced similar. We all freaked each other out a little, and decided to talk about something else.
As it happened, a few days later my Wife and J started discussing this again when M came home. He worked a lot of long hours at that point, and added that funnily enough he too had experienced similar. One early morning he'd come home, and while putting his bag down, out of the corner of his eye, he had thought he'd seen a figure standing in the doorway between the two houses. Just for a second, though. When he looked up there was nobody there. But it had freaked him out something silly.
From that point onwards of course, all 3 were actively looking to see something every time they were downstairs.
They even took to addressing 'The Ghost' as they were caling it by then, every time they entered the house or came down the stairs...
My Wife didn't stay in the house much longer. Not through fear of some kind of haunting, mind. Because the Landlady began to become a more increasing nuisance. She didn't renew when her six months were up.
A couple of years after leaving, when my wife and I had actually moved into a house together in the next town, we actually learned that Castle Hill and High Street (Which the road becomes further up the rise) are reputedly in the line of a 'Monk's Walk' pathway, leading down to the Castle, which pre-dated all of the old building along the row. We are apparently far from the only people to have reported seeing *something* walking through their ground floor rooms across the years. We had no idea of this particular legend at the time, and just thought it was weird stuff happening in HER house. But it seems it might be a further spread phenomenon.