Welcome to the forum! More detail is needed. There are many external light bulbs on a trailer and we don't know which one you are referring to. Pictures are worth 156 words.
I have a Jayco Flight Swift 267 BHS. It's the external orange light on top, right next to the door.
In hindsight I should have taken a picture. Unfortunately I already fixed it temporarily with duct tape (which actually looks pretty good so maybe that's the fix )
I broke mine,so I put as may short strips of LED strip lights in it as I could make fit and wired everything togather.
Easy fix ,plus lower draw on the battery.