There is a risk that the cardboard could catch fire in the oven while baking the pizza. Even if the cardboard does not burst into flames, it could scorch and ruin the pizza. Another problem is that the cardboard would hold moisture underneath the pizza resulting in a soggy crust.
Aluminium foil will darken in contact with heat and moisture but shouldn't catch fire in your oven.
Cardboard one would just blacken on the edges. Styrofoam would melt and probably catch fire.
I think your question is "Does foil catch fire in oven when on cleaning mode?" If so, Foil catches fire if it is contaminated with grease/oil type. It does not have flammability.
English muffin pizzas smores hot dogs
A solar oven is made up of aluminum panels and won't catch on fire itself. However, it is possible for the food being cooked within the solar oven to catch on fire much like a magnifying glass focusing light from the sun can catch a leaf on fire.
You want to clean the oven, particularly if you have spills so that they do not catch fire next time you light it up to cook.
There is a possibility, depending on strength, size, if they will catch fire in the oven, etc.
Put it in the oven.
Plastic wrap will melt or possibly catch fire if placed in an oven, as it is not safe for high temperatures. This can release harmful chemicals and fumes into the air, and is a fire hazard. It is best to avoid putting plastic wrap in the oven.
cookies,brownies,cake,
Metal in a microwave oven is not a good idea. Many sparks. May cause a fire, especially if there is also paper or cardboard involved.