Question about spanking

I have an interesting fantasy, but I am not sure how to make it a reality. I want to be spanked by a stranger. I am an over weight middle aged lady...not bad looking, but not what mainstream world calls hot. I am curious as to how many guys would be willing to participate in a fantasy like this. There does not have to be sex involved, but it is a possibility. I just want to ask a stranger to spank me but I don't want to deal with a lot of rejection. For any guys who may read this. ..how would you react to something like this? Any advice on how to ask in order to increase my chances?