This Vanguard utilities ETF isn't exciting, but it is reliable and focused on a sector that is likely to see material growth in the years ahead.When investors think about utilities, they most likely think something along the lines of, "boring dividend stocks." That's a legitimate view of the sector, which is known for providing reliable dividends. In fact, the average utility is yielding around 2.8% today, which is more than twice the level of the S&P 500 index.Buying a utilities-focused exchange-traded fun ...