Since there are two ports on the cf-ew72, I have one port using POE and access to my router. I was wondering if I could use the second port as an access port and run a cable to my switch, creating a two port managed switch?
Technically, yes - but what's the point?
One port in, one port out - and both are limited to 100BASE-T. 100 MBit/s ethernet is already a ridiculous combination for an 802.11ac radio (it would already be for 802.11n), but then using that to connect a switch?!
Better to go the other way round, connect your switch (there are PoE powered ones, even with OpenWrt support) and only use the CF-EW72 as a leaf device.