Missing instructions but it should stand out if you’ve ever seen it 😀
This is part 61406pb04 Plate, Modified 1x2 with Angular Extension and Flexible Orange Tip, which comes in 2 sets:
It sounds like you're going through a large collection, so may have this question again.
In general, if you have a LEGO part you don't recognize, the best thing to do is to search for the four or five digit design number on the underside. (It's small on many parts, molded into the plastic in the recesses.) In this case, the design number is 61406. There are several websites you can use to find it based on the design number; Brick Owl is one I'm fond of.
From there, you can look at the sets that used (and others with the same design but different colors) to get a sense of its usual use.