I agree. However, the chances for big frauds in broadcasting are limited because local radio and TV stations are not big business at that level. And because radio and TV is very visible, any attempts at fraud get caught.Legitimate nonprofits undergo strict scrutiny, but anyone can play fast and loose with a stacked board of directors, outright deceit and slick bookkeeping until or if they are caught. It's a tempting target for grifters who prey on people's good intentions. Broadcasting is not immune from these abuses. People must be careful who they give money to and how much actually goes to the avowed mission and how much for "administrative" purposes. Big charities are regularly rated by watchdog groups, but smaller ones can slip under the radar. Being wary is just being wise.
@Hagarty has posted many descriptions of the fraud at the public station in Sacramento. It was uncovered and the perpetrator charged. So, yes, to your point,, there are cases. But they usually get caught.