"Alfred Hitchcock Presents" premiered this day in 1955. It featured the portly master of mystery weaving tales of suspense and twisted endings. Our homes, too, are filled with lots of mysteries and twisted endings -- like those special waterline fittings under the sink called compression nuts. Typically these fittings connect the water supply to the faucet, and the inexperienced often try to guess how much to tighten the nut on a compression fitting -- with disastrous results. You can easily over-tighten a compression nut; to avoid this, use these easy-to-follow Carey Brothers' steps: First, slide the nut onto the copper pipe, then the ferrule -- the proverbial brass ring. Then slide the pipe into the fitting as far as it will go and tighten the nut by hand. Then turn it one more revolution with a wrench. Turn on the water; if it leaks, tighten a bit more gently until it stops. That solves the mystery of compression nuts and just how much is enough. And that's the On The House Tip for today.