Alarm system cable type (is ethernet cable ok?)

[surveillancelot]

I'm reinstalling a few sensors, and I was thinking about rewiring those, since the old cable needs to be removed anyway. I have plenty ethernet cable still left from camera installations, and I was wondering is it ok to use it for the alarm system. Sensors are normal 12V. If it's ok, does it make any difference which wires to use for signal and power?

 

[SyconsciousAu]

Security cable is 21AWG and Cat 5 is 24AWG, which means it has half the cross sectional area. I wouldn't do it. The right cable is cheap.