Brake light issue

I'm having issues with the passenger brake light. I'm going through bulbs, they keep burning out. I don't know if its a fuse issue or the harness issue. But need direction on what it could be. I'm thinking it may be the socket but not sure where I can buy a replacement.

 

Here you go. Your local dealer may have them in stock. Look at the contacts where the bulb seats and see if there is any rust....that is common to find.

https://www.sparksparts.com/v-2014-toyota-tundra--sr5--5-7l-v8-gas/electrical--bulbs-chassis