Like I said, use the copy path button to set the property of the switch node...
Working demo...
[{"id":"eb4f36e6.99ee28","type":"inject","z":"b872cb4b.5a6448","name":"","props":[{"p":"payload"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"","payloadType":"date","x":1560,"y":500,"wires":[["5996ddc4.3a43a4"]]},{"id":"5996ddc4.3a43a4","type":"function","z":"b872cb4b.5a6448","name":"alarm (fake DB call)","func":"var state = ((new Date()).getSeconds() % 2) == 0 ? \"disarmed\" : \"armed\"\nmsg.payload = [\n { status: state}\n]\nreturn msg;","outputs":1,"noerr":0,"initialize":"","finalize":"","libs":[],"x":1580,"y":560,"wires":[["99f1346c.b4a398","169fa35.0baf15d","fb94acac.45248"]]},{"id":"99f1346c.b4a398","type":"switch","z":"b872cb4b.5a6448","name":"","property":"payload[0].status","propertyType":"msg","rules":[{"t":"eq","v":"armed","vt":"str"},{"t":"eq","v":"disarmed","vt":"str"}],"checkall":"true","repair":false,"outputs":2,"x":1770,"y":560,"wires":[["8ad0987f.573b98"],["dc361739.8ae068"]]},{"id":"169fa35.0baf15d","type":"debug","z":"b872cb4b.5a6448","name":"","active":false,"tosidebar":true,"console":false,"tostatus":false,"complete":"false","statusVal":"","statusType":"auto","x":1570,"y":620,"wires":[]},{"id":"8ad0987f.573b98","type":"debug","z":"b872cb4b.5a6448","name":"armed","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"payload","targetType":"msg","statusVal":"","statusType":"auto","x":1970,"y":540,"wires":[]},{"id":"dc361739.8ae068","type":"debug","z":"b872cb4b.5a6448","name":"disarmed","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"payload","targetType":"msg","statusVal":"","statusType":"auto","x":1980,"y":580,"wires":[]},{"id":"fb94acac.45248","type":"change","z":"b872cb4b.5a6448","name":"move to payload","rules":[{"t":"set","p":"payload","pt":"msg","to":"payload[0].status","tot":"msg"}],"action":"","property":"","from":"","to":"","reg":false,"x":1800,"y":640,"wires":[["66cdbb8f.f92b24"]]},{"id":"66cdbb8f.f92b24","type":"debug","z":"b872cb4b.5a6448","name":"","active":true,"tosidebar":false,"console":false,"tostatus":true,"complete":"payload","targetType":"msg","statusVal":"payload","statusType":"auto","x":1990,"y":640,"wires":[]}]