How does Priestly use the theme of inspection in An Inspector Calls?

Priestly utilises the theme of inspection in An Inspector Calls to conjure the consciences of the characters and invoke a sense of guilt. Priestly's play centres around the idea of inspection and interrogation, as suggested in the title. An inspector comes to the Birling's house with the news of Eva Smith's suicide and proceeds to interrogate each character individually. As the play unfolds, it becomes clear that all of the characters share a portion of blame for the death of Eva Smith. In singling off each character, the inspector instantly forces the interrogated to feel unease and to react defensively. In this way, Priestly uses the inspector to symbolise the inner conscience, demanding the characters to consider the impact of their actions.
It could be argued that Priestly used the theme of inspection and the inspector to represent a God-like figure, demanding right and wrong to be established and to punish those who acted wrongly and sinfully. The arrival of the inspector is random and unannounced and his behaviour is firm and authoritative. By the end of the play, the reader is left questioning whether the inspector ever actually visited at all, or if it was the guilt of their collective consciences that provoked this outpouring. Arguably, the name of the inspector, Goole, is a play on the word 'ghoul', evoking a mysterious and invisible presence that arrived to reveal the wrongdoings of each character. The inspector, in questioning each character's morality, comes to symbolise all that is good and right.