The interviewer is looking at your capacity for being concerned with safety in the workplace and at home, as well as the desire to prevent accidents and check for hazards. Don't just throw around the word safety - be specific in your answer. Think about what you do at work to be safe - wear proper PPE, attend safety meetings, follow all policies and procedures. At home, think about the types of things you do to be safe now versus before you started in your technical field. You might do things such as wear proper PPE to mow the grass, have someone hold the ladder when you stand on it, and diligently maintain equipment in your home.