Changed this back, about to change the other page about the spiderhouse guy. (Did it more to make sure this note didn't get forgotten in a Talk.) Anyways, it was the act of putting the mask on that transformed him. That means that the mask itself had a part in the "greed" part of the curse: more to the point, attempting to read the instructions in the mask is what triggered the curse.
Feel free to rebut.
(It's technically true that the instructions were in the house because the mask was in it in a certain sense, but that would be unnecessarily vague for this site in my opinion.)