I'm a no
I have a "smart plug" that turns the whole room off when the PC shuts down .... the router(s) + switches and phone charger are plugged into their own supply.
Provided you have some security enabled (WEP / WPA) it's no problem. A friend had his wifi connection hijacked by a neibour because he left it on and had no security. At least put your MAC addresses into the router.