Yes, every electric switch I've seen for a break-away circuit uses an open switch that closes when the pin is pulled. Break-away switches for cable operated braking systems use a 'switch' that clamps down on the cable when emergency braking is required.
Your system can easily be tested, just connect the two wires together at the brake box and see if it applies the brakes. On my unit, a simple RCA plug is used to connect to the break-away switch.
Bob & Donna
'98 Gulf Stream Sun Voyager DP being pushed by a '00 Beetle TDI