When I'm needed, I wish I wasn't.
When I'm not needed I won't have what to do
What do I do, what am I?
Life still occurs, birth will ultimately result in death
Hint (Due to being put on hold for being 'too broad' I decided to ease this with the following)
Think of someone who only has a job as long as people die unnatural deaths
I'm the one that has to think about what the coroner tells me