What is the best way to check the wires in your house?
Modern copper wire does not wear down nor erode. At least not for a millennia of time. If your house wire and electric system was installed by a state licensed contractor than you don't need to worry. If you're not sure who installed the electric system and feel that there may be a potential problem, than you would be wise to call a local electrician and have him or her check and repair any issues. If you want edit your question with more detail and specifics (flickering lights, breakers shutting off regularly, breaker panel under- rated, etc.?) you may get a better answer.