This story took place in Scarborough, a part of Toronto, in the mid-1990s.
We lived in a storey-and-a-half house that backed on to a cemetery. I'm not suggesting that's relevant. It's just a fact. The house was built around 1949.
This happened when we're doing renovations on the second floor and remodeling the kitchen.
I had an office in the basement of the house. My wife worked upstairs. On the main floor between us we had a living room that contained some Mission-style furniture, including a large double-doored glass bookcase. One weekday around 6:30 pm in late summer, I heard a loud crash above me, just where the bookcase was located. More than just an indistinct noise, I heard the impact that a heavy bookcase would make if it toppled over and the resulting crash of the glass vases on top of it. I heard the glass breaking and heard the scratch of glass shards skittering out across the floor in the direction one might expect through the ceiling above me.
Thinking my wife might have been injured I ran upstairs and asked if she was OK. At the same time, she ran downstairs and asked if I was OK. She described hearing the same noise, expecting it was the bookcase, but the bookcase stood exactly where it was expected to.
A thorough search of the house revealed nothing had fallen. There was no room within the lath-and-plaster walls for anything to have fallen there either. Checked outside, checked the roof, checked the knee wall crawlspaces on the second floor. Nothing. We spent probably an hour looking for a cause and found absolutely nothing relevant. More puzzled than frightened, we gave up.
The next day, I drove my wife to have dinner with her mother. Returned home at 6:15 pm. I started working in the basement office and at about 6:45 pm, heard a complete repeat of the occurrence from the evening before. A massive crash, same sound of breaking glass, same spread of glass across the wooden floor. I went upstairs to find everything where it should be. A similarly thorough search of the house, both inside and out, revealed nothing.
I'll admit the second occurrence unsettled me, but we never heard a disturbance this loud again.
There was one additional oddball sound, however. When we walked across the bathroom threshold on the main floor, we would often hear what we called the "Star Trek" noise. It sounded a bit like the transporter from the original TV series. We could not reproduce it at will and we had no idea what caused it. After hearing it one day, I remember being determined to figure out how to reproduce it. I crossed the threshold literally hundreds of times to learn how to make it happen - and it wouldn't. My wife was watching me, and laughing at my effort. I finally gave up and walked across the threshold to leave the bathroom one last time - and we heard the noise once again! I repeated exactly that same footfall in the same direction another 20 times: nothing!
This never unsettled us. It was just amusing.
Star trek (not star streak) I missed that error. Sry folks.