Jeep Grand Cherokee rear running lights (tail lights)/brake lights not working

I was once told by a senior couple at a shopping center that one of my brake lights was out. I replaced the bulb and was out once again soon. I was also told that the problem was that the heat melt some part of the plastic assembly and caused circuit short or loss of contacts between electrodes -- I replaced the assembly without a cure.  Since I saw many many Jeeps have the same blind eyes on the road, I then have been ignoring this problem (for three years) so that I could save my time and effort.

Last Saturday my wife gave me a ride from a party (lots of wines!!), it was almost home when a policeman flashed his fabulous lights. I told my wife not to panic since it must be the broken brake and tail lights -- the only thing is that  there is no way to keep a blind eye to the problem any more.

After a careful test, I found that one brake bulb was out. But the right tail light did not work any way. Checked the fuses, no luck. Assembly is a newer one.  What else??

The bulb SOCKET is the last suspicious culprit which I can imagine. The good thing is that the sockets are not expensive -- USD 7.95 from the online parts department of a local dealership -- not expensive anyway. I ordered six for about $60.

The parts arrived in one day. It is a piece of cake to take down the socket with a screw driver. The only thing is that one needs to turn the socket counterclockwise til it cannot move under finger force. Then use a flat screw driver to pry it out. -- install it later in a reverse way. The following is the picture of an old socket with burnt butt.

Put the new ones on. A long time headache is gone.