I want to use a small slide switch to turn my circuit on and off so that the circuit draws no/very little power when off. The circuit will only draw a maximum of approx. 500mA @ 5V when on, but to my surprise the switch I want to use is not rated to this. So I decided to use an N-channel MOSFET to switch my circuit on and off. Part number for the MOSFET is DMN3404L-7. A bit overkill, I know.
Header P1 is the power supply header for the entire circuit.
I am wondering if this is a proper implementation of an N-channel MOSFET. In particular, is there a good reason why I should not connect the drain port to common ground as shown? Also would a P-channel MOSFET on the high side be better suited for this?