New Mexico University points out that the Scoville scale is a subjective spiciness scale and some people can be more sensitive to capsaicin than others.
We used to call the ground seasoning paprika, which is sold in the spice department, and when we mention bell pepper, we present sweet fleshy fruits with a characteristic aroma. Many people associate red pepper with long, pungent pods.
So the question of what is a good paprika substitute comes down to what dish you're preparing and how much paprika that dish calls for.