So, to supplement a Jet air cleaner in my shop I'm going to build 1-2 similar units using 110 furnace blower(s) and off the shelf filters. I've seen several DIY plans that I like. These will be wall mounted, and hard-wired. I want them to run any time the lights are on in my shop, but they will be on a separate circuit from my lights-only circuit. What device or gizmo do I need?