Missing episodes?

I’m not sure if it was black mirror but from my memory it was. I watched the whole series a few years ago and for some reason I remember and episode very vaguely. It might be a shamble of two different things so someone correct me if I’m not making any sense. It was a girl residing in a town. The thing was for one reason or another she wasn’t supposed to go far, although out of curiosity she was walking along the beach and suddenly discovered a huge mansion and didn’t approach it rather headed back and tried telling people about it although nobody sided with her. She ended up going to the mansion and it was filled with rich people dressed up and they welcomed her like it was nothing. I think at this point I fell asleep although it was incredibly interesting and the people in the mansion were pretty twisted from what I remember.

Now that I’m typing I also remember an episode where a couple had died and in the after life they still lived in the same house in the same neighbourhood but the people around were different, other diseased people from a time before. They key was the neighbour who wasn’t always around but was heard doing loud work at night, it was a woman. They eventually had met and got into some sort of crazy event to which I also don’t remember how it ends.

I’m 99% sure these weren’t dreams from 2 years ago that I’m mixing with other memories. But I don’t see anything like either of them on black mirror, where did these memories of movies come from and what are they called?