Maybe its just a housequake. Well, that is a very local earthquake. In all these cases, the earth shakes in response to a local shock. These shakes would show up on a seismograph. On a larger scale an explosion can cause the earth to shake for a considerable distance.
Scientists use seismographs to monitor nuclear tests.
People in Las Vegas could feel the shaking caused by underground nuclear tests in the desert miles away. Every day tiny meteors hit the earth, as we move through space. The vast majority of them burn up in the atmosphere, leaving no more trace than a shooting star across the sky. Once in a while, a meteorite will reach the surface of the earth. Very rarely a great meteorite will hit, causing the ground to shake and creating a large crater.