Sandberg has put a small adapter on the market that protects against fire if you have cable TV.
The reference earth, which comes into the house with the cable TV, is usually different to the reference earth that is in the house's power sockets. This can create dangerous situations when the aerial cable is connected at the back of a flat screen, media centre or hard disk recorder, for example. Sparks and heat can be generated, which in the worst case scenario can result in a fire breaking out.
The Sandberg Antenna Galvanic Protector is a simple transition piece that solves this problem. The galvanic separator keeps the different reference earths away from each other to prevent sparks and heat developing.
In several countries galvanic filters like this one are a legal requirement. It's certainly a cheap way to prevent fires too, irrespective of whether you live in a country where you must have one by law.