The vast majority of Raid products utilize one or two active ingredients which are typically one of the synthetic pyrethroids. These compounds are direct contact insecticides or are eaten along with a food source upon which the insecticide was applied to its surface (e.g., insecticide sprayed on a leaf surface then eaten by an insect). Synthetic pyrethroids are not translocated within a plant's vascular system nor taken up from the soil through the roots (https://extension.oregonstate.edu/catalog/pub/pnw-772-pesticide-redistribution-its-implications-pesticide-efficacy).  The concentration of the active ingredients in a Raid aerosol product in very low and would be further diluted by the water used to hose the wasp nest from under the stairs. The half-life of these chemicals in the environment is days to a month or two depending on environmental conditions. When these chemicals are exposed to UV rays from the sun, their breakdown is rapidly accelerated. 

So, unless the Raid product is sprayed directly on a food or onto the surface of a utensil or plate from which food is consumed, it is not a threat.