Dreaming of walking on a treadmill can symbolize the feeling of being in a repetitive cycle or working hard without making much progress. It may reflect your current life situation where you feel like you're putting in effort but not moving forward as you would like.

The mischievous child in your dream could represent a playful or unpredictable aspect of yourself or someone in your life. This child raising and lowering the treadmill level might suggest that there are external factors or influences that are affecting your progress, making it feel easier or harder at different times.

Overall, this dream could be encouraging you to find balance and take control of the factors that affect your progress. It might also be a reminder to embrace playfulness and adaptability in your approach to challenges. Consider reflecting on any areas in your life where you feel stuck or where someone else might be influencing your journey.