Then you'd need the USB Ghost Radar.
No, I am not joking.
( Dave Trouser ; the people's choice - 75% agree, Wed 3 Jun 2009, 18:01, archived)

*looks this up*
I wonder if it would be able to detect the Ghost of Wolrige Road.
( Moon Girl Technologies horrendous beanbag, Wed 3 Jun 2009, 18:02, archived)