Presence of a large number of wireless access points can be sensed in airspace of a typical enterprise facility.
False positives occur when the wireless intrusion prevention system detects an access point not actually connected to the secure network as wired rogue.
False negatives occur when the wireless intrusion prevention system fails to detect an access point actually connected to the secure network as wired rogue.
Among the external access points, if any is found to be mischievous or a potential risk (e.g., whose settings can attract or have already attracted secure network wireless clients), it is tagged as a rogue access point of the second kind, which is often called an "evil twin".
This makes it possible, without the need of a physical Wi-Fi router, to share the wired network access of one computer with wireless clients connected to that soft AP.