Interior light in trunk

[ScottB2460@aol.com]

This is probably an electronics 101 question, but my interior trunk lights
has not worked in quite a while, no problem I'll get a new bulb.  Well, last
night as I am  unloading the trunk from a Walmart run, the light comes on.  I
poped the plastic cover, pulled it out and it flickered as I pulled it, and
went out completely.  I went to put it back in and when the metal connection
on the bulb touched the metal frame of the car, the light came on.  Is this a
short of some type?  If so, what can one do to fix it.  FYI, I pulled off the
connections and put them back on and they were clean on snugly on there.  

TIA,

Scott
89 200tq