That depends:
What is the voltage and wattage of the light bulb?
Is it fluorescent, compact fluorescent, incandescent, or HID?
Is the light in or near a pool or bath tub?
What size branch circuit is feeding the light bulb?
Is the circuit between the light bulb and the panel properly wired, and grounded?
How many other light bulbs are on the circuit, it may not be safe to change it?
What is the voltage and wattage of the light bulb?
Is it fluorescent, compact fluorescent, incandescent, or HID?
Is the light in or near a pool or bath tub?
What size branch circuit is feeding the light bulb?
Is the circuit between the light bulb and the panel properly wired, and grounded?
How many other light bulbs are on the circuit, it may not be safe to change it?