Adding a relay to lower the amperage on a switch?

What this means is that the electric contacts in your switches are rated for a maximum of 15 amps. You can purchase a relay that is rated for higher amps. In that case, the switch would only activate the relay. The relay would act as the switch for the heavy amp draw item. I would think you could find a relay at an auto parts store. They come in many amp ratings. Hope this helps.