For some people, the threat that is feared the most is the threat that they cannot see. This is understandable, since if you can see your threat, you can assess how you can best deal with it. Something that tends to be a threat to the health of the people in your home is mold growth and if you have this in your home, you may or may not realize it. Sometimes mold is hidden inside the walls, ceiling, or floor, and we will not know without having a mold inspector come to the house and do some testing.
You can do an inspection of your home for visible mold growth, though, fairly easily. Sometimes you will run across a splotchy patch of drywall in your bathroom or other moist room in your home and you will instantly be able to identify that there is a mold problem in the house. Other times, finding the mold will not be this easy, because the mold is simply invisible. At least, when you look at it the wrong way. Finding mold takes a little detective work sometimes and this is best done with a flashlight.
If your home has wooden paneling anywhere inside it and you have a problem with mold in one area of the house, turn the light off in the room with the paneling and shine the flashlight along the surface of the wood. This will give the mold a little bit of depth and it will show up much better than if you shine the light directly onto the surface at a 90 degree angle. These molds usually belong in the genii Aspergillus or Penicillium and are very easily overlooked if you do not use this flashlight method.
You can clean the mold off the wood paneling with chemicals that are advertised as being able to kill mold, but you may want to be careful just what you put on the surface if it is real wood and not imitation of any kind, especially if you plan on keeping it as a part of your home. If the growth returns after a few days or weeks, though, you may want to consider removing it completely, since the growth may be embedded into it.
The reason for wood paneling in some homes is that they have been flooded and the previous owner could not afford to put drywall back in the damaged areas. If you can afford to remove wood paneling that has no drywall behind it, you really should do this. Replace the paneling with paperless drywall, since mold has a harder time growing on these slabs of drywall than others.