What does “귀신도 먹고 살기 힘들구만” mean?

See a translation

In literally, "ghost(or devil, satan, spirit, soul) tighten his belt too."
But this expression can be changed easily according to what is the ghost's todo which speaker expresses.


There is a korean proverb "귀신은 뭐하나 몰라, 저런 놈 안잡아가고"
Literally, "I don't know what are ghosts doing, instead of catching that guys." (It is a proverb, so it is hard to translate.)
In this case "that guys" is very bad(or cruel) people(e.g. murder, traitor, child rapist) and ghost's todo is arresting criminals(to be exact, take them to hell)
So police catch them very well, there is no ghost's todo and ghosts have to tighten their belt. Because they have to work to make money but no works.


Also, there are newly coined terms "사탄(악마, 귀신)이 실직할 지경", "사탄이 혀를 내두를 지경", "사탄이 스승님으로 모시겠다 하겠다"
Literally, "The situation that Satan(or devil, ghost) is fired", "Satan is astonished", "Satan would say 'please, be my master'.", and this sentences have same meaning that someone do something more skillful than Satan.
In this case, ghost's todo(to be exact, Satan or devil comport than ghost) is something about evilness, cheating, and all of what typically devil do.
So if there are many people who do evil something(e.g. crime or even if not crime but something what is same level), there is no ghost's todo and ghosts have to tighten their belt.

In addition to examples, this expression can be changed easily according to ghost's todo. If you want to know meaning, you have to read the lines.

ps
Second examples like "사탄이 실직할 지경" are not always used only serious situation. As a joke, you can use to express about extraordinary monkeyshine. It is just a newly coined term.