Melting tail light bulbs repeatedly

Hi All

Been a while since my last post but my 2005.5 Jetta has decided to start burning up right tail light bulbs. Pull bulbs and the bases on the bulbs are melted to the point that the access to the inside of the bulb is open. I have replaced 6 bulbs in the last couple of months.

Cleaned the contacts very thoroughly before last replacement and 3 days later bulb bases burned off....

Always the right tail light both bulbs

Thoughts

Just some ideas here...

Chinese bulbs?

Wrong bulb with a higher wattage maybe?
Tail light bulbs are meant to be on for long periods of time. Brake light and turn signal bulbs are only on intermittently. Being that the latter are brighter and higher wattage they create more heat. To mistake the two can melt the fixture plastic, too.

are the contacts springy enough?