Five. Four to decide which way the bulb ought to turn, and . . .
or
A crane.
or
It takes two. One to change the bulb, and the other to kick the switch.
or
Because pepper makes them sneeze
or
Twenty. One to hold the bulb, two to turn the ladder, and seventeen on the guest list.
or
Two: One to screw you out of a fee, and the other to send you to a store where they ran out of bulbs weeks ago.
or