The Echo has this thing called “skills.” A skill is a bit of software that provides the device with some sort of ability. (see for example this post on a math-building skill.)

Once you have the Echo, install the Away Mode skill. You can get it here.

Once installed, Away Mode allows you to tell your Echo to play a long and involved audio of actors playing out various scenarios. If the volume is correctly adjusted, potential home invaders will hear this as conversations happening inside the house, and say away.

These are totally realistic scenes. For example, there is a book club meeting where everything except the book is discussed. It runs for 6 minutes. There is a guy planning a podcast about himself, an emergency PTA meeting to discuss fidget spinners, and a couple having a breakup while also watching TV. In other words, your life.