Switch power can come from a switched or unswitched location. It boils down to when you'd like the trunk release to function. If you want it to function at all times, power can come from a fused power source such as the cigarette-lighter circuit. If you want power only when the ignition switch is on, get it from the ignition switch (1967) or from a switched underdash pigtail (1968). Regardless of where you get power, it must be protected with a fuse.