I have 6 dogs, some are rescues and they really are skittish around anyone, it is because of lack of socialization as puppies. 3 of the dogs we’ve had since 6 weeks, I take them everywhere, they are used to all people.
The 3 that are not socialized are also freaked out by a cardboard cut-out of the Worlds Most Interesting Man (the Dos Equis man)...he is white with a beard...I have come to use him to keep the dogs off of furniture, out of certain rooms etc. It really is funny that this cardboard man has so much control over them.