I feel quite lucky to have just finished reading about WILD and to have found this post. It is quite exciting for me to put these experiences together and put a name to it. This is truly a great and informative website.

I have that "vibration" happen quite frequently too. In fact, I used to think it was my house vibrating either due to ancient a/c-heating system on my roof or earthquake (very frequent where I lived). Then I recognized it happening wherever I slept. -Even now, 3000 miles away.

I have SP frequently as well. I've always found them to be quite defined and easily recognizable (and so tends to be a very good trigger for LD). I had never thought to look at the vibrations as a pre-cursor to SP, nor to link SP and WILD.

I'm happy to see the experience has been shared by someone else, though sorry it freaked you out.