Opened up a switch plate on a kitchen light switch…found quite a bit of sawdust inside. Worried about carpenter ants. Have not seen any ants in my kitchen, just little tiny mite-like things. -Jeff E.

Jeff it sounds like you may have two separate problems all together.  If you squish the mites and they leave a red mark then they could be red spider mites.  If you clean out the saw dust tonight and it returns tomorrow then you have something actively damaging your wood.  Carpenter ants will leave sawdust. Carpenter Bees leave sawdust as well.  Termites don’t leave sawdust as they actually consume the wood.  You will want to check around the outside of your home for the carpenter ants.  Its possible that the saw dust could be from a previous infestation if this is the first time you have seen it.

But with that said, the best thing to do to get rid of an existing infestation is a whole house clean out.  And you should maintain a barrier to keep the bugs from coming back.  Ant trails can last up to a year, so just because they are not there now doesn’t mean they won’t return. Maintain a protective barrier is key to keeping your home pest free.