Last night 02;20 I awoke to a rap rap rap etc. Someone pounding on my door or maybe the neighbors as it wasn't real loud. I also was half sleeping.
Enough for me to go downstairs and check it out. Nothing.
Later the same thing happened I followed the sound and a picture in the hallway on the other side of my bedroom wall was vibrating!
I tilted the picture slightly and the noise went away.
I live two long blocks probably 4 average ones from the railroad tracks. It was the trains shaking the house slightly.
I haven't been bothered by the trains for a long time and my last house was much closer to 2 different tracks.