Question

I want to, and maybe even need to, ask my boss for a raise.
On the other hand, there is a fairly high chance that he will refuse and may even fire me.
Maybe it is better to stay with what he gives me today than to end up with nothing.
Or perhaps it is better to ask for a raise and manage better in life than to take the risk and remain with the low salary.
 
What is the proper thing to do?
It should be noted that this is a rare job (almost no work at all, while bringing home a reasonable salary), and it would be very hard for me to find something else under these conditions.