I think asking outright is a difficult one because haunted could mean so many different things. And houses can feel completely different to other people. I think you would just have to view the house and get a really good feel for it, perhaps ask about the history although I don’t always think an unsettling history = haunted.
I’m not sure I believe in ghosts necessarily but I think homes to have an energy about them. Ive been in really unwelcoming newer homes and felt completely relaxed in older ones.
I’ve lived in a Victorian doctors house previously which had a small chapel of rest style room in it , people in the village used to frequently tell me about all of the relatives they had had laid out in there. Never had any strange vibes though.
Same in my current house that’s 400 years old, all quiet.
However I think there are instances where you instantly get the no-go vibes. Years ago I went to view a house, my mum came along for company. Lovely house, not that old really, probate sale and really well priced. Met the estate agent on the drive who simply said ‘it’s open, see you shortly’
Thought it was a bit odd he didn’t come in but carried on regardless. If a house could have screamed “f**k off” the minute you went in this was it. The silence was deafening and you just felt horrifically unwelcome, we walked out after a minute. Estate agent laughed and went ‘let me guess, not for you?’ He said he had lost count of the viewings.
Turns out the house belonged to an old couple who had lived there for decades. Wife died and a few weeks later the husband went too. I swear those two were still in that house and didn’t want anybody else there! It was on the market for months after, I assume it eventually sold. But it was a truly awful feeling being inside it…..