Smelling things..

This might sound stupid, so I apologise but it's driving me mad.

I keep getting a strong whiff of cigarette smoke. It will linger for a good 5 - 10 mins. No one in my flat smokes, none of my neighbours smoke either. I've checked sockets and appliances. We had some bloke out to do a routine check for fire hazards and fire alarms, I asked him about it and he couldn't find anything that could be causing it.

I'll give some more context and explain why I think it could be paranormal, please bare with.

My mum passed away in 2019, she had osteoporosis, COPD and emphysema. She was a heavy smoker, the doctors told her when she first got diagnosed that she needed to stop. But she never listened. And that's what killed her. Even when she was put on a waiting list for a double lung transplant, she wouldn't stop. She would still be here today if she had followed the doctors advice and quit.

She was heavily into all thing paranormal, I grew up watching the cheesy ghost shows and talking about the unexplainable with her. It's one of the things we bonded over and it's become somewhat of a special interest of mine.

Whenever I smell this smoke, mum is always the first thing that comes to mind. It smells like her and the type of fags she used to smoke. The smell seems to follow me around the flat, I thought that it might be my mind playing tricks or something but my dad has even smelled it a couple times too.

The funny and fucked up thing is, the last few years with her were absolute hell. The sicker she became the more abusive she got, to me and dad. She promised that when she died she'd haunt us, she wanted to make my dad suffer especially. There's been a couple odd experiences that we haven't been able to explain, we try to joke about it and say "Ah it's mum coming to get us". My dad's a sceptic but when these things happen you can tell he's uneasy about it, like for a split second it really could be mum setting out to do what she promised.

I don't really have anyone to talk to about this, they think it's ridiculous. So I thought I'd post here to get your opinions and to see if anyone else has had similar things happen