There's a key too sensible, can it be repaired?

Y got this keyboard second hand, after some time figured out that a key (B in this case) is too sensible, just holding softly the finger on it gets pressed, this does not happen in other keys, I understand that something is broken in the inside, do you think this can be repaired? I've heard that this can be the membrane, and is costly, does not worth it, any clues? Thanks in advance.