To find out where the other end of a conduit terminates, squeeze in a couple of ounces of colored carpenter's chalk. Put the shop vac on exhaust, and blow the chalk through the pipe. If conduit terminates at the box, the box will be covered inside with the colored chalk.
The continuing advances of power hand tools receive much attention, and many are linked directly to lithium-ion battery platforms. Tools are lighter, more powerful for their weights, more productive and easier to use.