I'm convinced my house is haunted by my nana ... which is understandable considering it was her house

She was a big joker, she said just because shes dead doesn't mean it will stop.
Anyway one time on her birthday I heard weird noises coming through my PC speaker, it was as though someone was speaking. Nothing was running at the time, the PC was unplugged
Another one on her death anniversary the living room door just swung shut and sh*t me and my mum up
Then another time there was smoke coming from where her chair used to be (we got rid because we did the whole place up)
And a few months ago I'm convinced I seen her stood at the kitchen door. I dropped my plate and it smashed on my foot, and food went everywhere