By using the fact that particle creation occur in formations of compact horizonless objects, at- tempts to distinguish between a black hole and an ultra compact object are made in spherically symmetric shell models. These analyses reveal that radiation from compact objects has two burst: post-Hawking burst and late-time burst. However, these models are using hollow shell and not real- istic for compact objects. Based on the above situation, we study particle creation in more general shell model, and find that behavior of the radiation power from a compact object have a kind of universality. This universality means that the radiation power of particle creation with a formation of compact objects does not depend on the detail of inside matter under an assumption.