Mazda 3 interior and tail lights flicker

I have a 2004 Mazda three and sometimes
when I turn on my car and turn the lights on,
the interior and tail lights do not come on but
the headlights do. When I drive like this and
hit a bump, sometimes the lights kick back on
and they usually stay on for the rest of the ride
so it does not feel like a blown fuse. What
could this be?