Cindy in Spokane, Washington, says her father would bid his loved ones good-bye by saying tap ’er light. The phrase comes from miners’ slang of the early 1900s and is a gentle admonition to take care to avoid cave-ins or prematurely detonating explosives. High-grade, meaning to select the best items for oneself out of a larger collection of items, is another example of slang from the mines. It’s a reference to a worker selecting some of the best ore and pocketing it instead of turning it over to the company. This is part of a complete episode.