Here's a warning for each and every one of you out there in DIY land. It may not seem to be a big deal to many of you, but believe me, after I tell you about my scary experience, you'll rush to your light fixture to be sure the right sized light bulb is in place. If you look on the box that a light fixture comes in or on the light socket itself, you'll see the maximum wattage bulb rating for that particular light socket.
If it says 60 watts is the maximum, don't put in a 100-watt bulb just because you want it brighter! There is are better ways of increasing the light volume and I will share a few thoughts in a moment.
As for the terrifying story, first, you must know that this incident happened at a rental for high-functioning citizens, staffed by supposedly competent employees.The manager of this home often wrote a list of minor fixes needed around the home from floor tile issues to light fixture issues. That's where the story gets scary.
You see, one fine day I get a call from her saying that something smells "hot" and it smells like it is coming from the kitchen light. I calmly told her to turn off the light and quickly proceeded down there to see what was the problem. Upon arrival and a quick climb up the ladder, I discovered it indeed was coming from the light fixture and that the light was very warm.
After removing the light fixture, I discovered burnt wiring to the light and also the NM cable insulation with a burnt brownish look. Checking the bulb size, I noticed that she had replaced all four of the 60-watt bulbs with 100-watt bulbs. Luckily for her, the patrons and I, that the house didn't start on fire!
Now, this is a real danger and a possibility in your home as well. It seems that people will screw in almost any size bulb that will fit into the socket. This same sort of issue was true years ago with screw-in fuses. Since the socket was the same size and depth for all sizes of fuses, you could take out a 15-amp fuse and replace it with a 30-amp fuse. The only problem was that the circuit was wired for 15 amps and there you go with another electrical fire potential. Then came the Edison-based sockets that had different depths for each size, keeping you from putting larger fuses in smaller rated sockets. Maybe that could be the answer for light bulbs.
Light bulbs can burn out from time to time and should always be replaced with the right wattage light bulb for the light fixture that you are installing it in. Matching the bulb to the fixture's specification will eliminate some safety hazards.
The manufacturer lists a caution sticker around the light socket area to warn the consumer of installing the wrong wattage light bulb. In essence, the manufacturer tells you something like, "in order to reduce the risk of fire, use a 60-watt type A or smaller lamp." This warning tells you what the maximum wattage of bulb to use and also the preferred type of light bulb, type A.
Using light bulbs of higher wattage than the fixture recommends could cause the fixture to overheat. This in turn often leads to an electrical fire. One warning sign to look for is a brown spot on the light fixture's insulation. Another is the wire insulation will become brittle from continued exposure to high heat from the bulb. And in the case of can lights, the fixture's built-in thermal trip will automatically shut the power to the light bulb off. If you have a can light turning itself on and off, you probably have the wrong light bulb in the fixture, causing overheating.