Please draw your network how you want it. You mention a VM, so is pfsense on a vm.. How is your your mv host tied to the network?
When using some soho router as just an AP, normally the easy thing to do is not use the wan(internet) connection of the router. You might be able to leverage it if your wifi router supports AP mode that bridges the wan interface with your lan ports and wifi. But many soho routers do not support that option. If you can put 3rd party firmware on it then you could most likely do that.
If you have a vm host that you want to leverage as pfsense and other vms, and then use some old wifi router as AP.. This wifi router does not also supply your internet currently does it? Its not a gateway is it with your modem/router in 1 device? Please draw up your current setup, and then how you wnat your future setup.