Another option of course is to learn how to access your routers internal user interface and learn the routers features and controls including how to turn on and off the router "radio".
That will, in one easily reversible "swipe" eliminate one entire "class" of potential problem avenues without disrupting a lot of cabling and so forth.
As an example, from my old Netgear WNR2000 user interface, the "wireless radio" portion of the router can be disabled/re-enabled by adding/removing the checkmark highlighted in this snip and "saving" the changes.
