Please respond when you can, no rush. It is a coincidence that lately I was quick with my responses.
Traditional source of ethics is religion and religious people derive their ethics from that single source; I am one of them. Of course, there is some latitude in the interpretation of Christian ethics, and I would imagine a similar latitude exists in other religions.
On occasion, a philosophical system replaces religion. Marxists for example derive their ethics from the perceived needs of the working class.
I don't think eclectic personal ethics are all that common.
I also say that various philosophical, social, and professional systems of ethics have always existed side by side with religious systems of ethics, except where religion outlawed such systems, and of course where such systems in effect outlawed religion. Equally, I do not agree that most Marxists derive their ethics from any perceived needs of the working class.
And finally, I say that "eclectic personal ethics" are not only the most common, but are almost unanimous source for ethics in America today, yesterday and all the way back to our countries founding.