when i have sex with my wife, my bed shakes too
hmm..
seriously.. (to you and everyone else)
when one encounter paranormal experience (especially of the negative kind), it normally means two things, listed in the relative of probability
1) some entity is trying to tell/warn you a good/mis fortune a around the corner
2) some entity is displeased at you, possibly because you disturbed the energy/field that they dwell in
it is also possible that they wanted you to help them to do/archieve something they need/wanted to do, but usually... if you are the kind of people
that capable of doing/giving what they want, you should at least realise this by yourself
.
.