Answer:
This risk is known as the overjustification effect.
Explanation:
This effect is a phenomenon in which an individual loses his/her intrinsic motivation (motivation from internal factors) because of being rewarded by something. This means the individual is less likely to do something if he/she is rewarded by outside factors.
In this case, since the individual is required to carry out community service because of external factors such as a requirement by a school or business, his/her motivation to do it in the future because he/she wants to will diminish, thus the overjustification effect is the risk.