Light bulb in tool cabinet

[Alex Holden]

Search for "tube heater" or "tubular heater". They are typically used to prevent frost in greenhouses. They are pretty cheap, you can get them in various sizes down to 1 foot/40W (that I know of - maybe you can find smaller if you shop around), the element runs much cooler than a light bulb so it doesn't burn out, they have feet/mounting brackets so they can sit on the floor or be screwed to a wall, the tube is made of plastic so is less fragile than a glass light bulb, and the surface of the tube doesn't get dangerously hot (the one I bought recently also had a thermostat in it for extra safety). Even 40W is probably more than you need for a small cabinet.

Edit: a bit of Googling and I found a 1 foot/30W one.

[george wilson]

I use a piano tube heater in my gun cabinet. I think they are safer than light bulbs.