Is it normal for a fuel pump on 1999 s10 pickup to make a light humming noise?

Depends on how loud the humming noise is. It may very well be failing. Change the fuel filter and hope for the best. A clogged fuel filter restricts fuel flow and makes the fuel pump work harder. This causes the pump to get hot. This is a common cause of fuel pump failure. you may want to change the fuel filter and see if that makes it stop, if nothing else it will make fuel pump last longer, not many people change there fuel filters. there inexpensive and a garage wont charge to much to replace it