In nature these mushrooms grow in the deep shade of the forest, so inside light is about right. They are okay with a little sun, but be careful not to let this dry them out. Interestingly the UV in sunlight will help them produce victim D in a similar way our body does.
However, they do not need light to grow (as a plant does) so they are okay without light.
The myth of mushrooms growing in the dark goes back to when the French began the mass cultivation of mushrooms in caves. This was because the cave had a constant temp and high humidity, rather than due to a lack of light. Not ironically they are called 'field' mushrooms for a reason, because they grow in open fields ...and in full sunlight! These mushrooms will in fact kill trees to create pasture for grazing animals (think of a clearing in a forest). The mushrooms then wait for a fresh pile of dung, which provides the mushroom with the humidity and warmth for the fruit body to grow, plus the substrate for the spores to later colonise. These types of mushrooms have an association with grasses and are one of the many important organisations that create soil.
This is also why growers of field mushrooms (like Buttons) are often in trouble for making a stink. They are often located close to poultry farms and collect the chicken poo (composted down) to make the substrate. Note: Our mushrooms grow on trees, so we use clean sa dust, so there is no poo or associated smell with our mushrooms.