sorry if i led you up garden path my fist question is will a -1 volt supply supply a current through a load to ground. and if so why? i don't understand negative voltages
and the second question
what would be the easiest way to implement it
Voltage polarity is always relative to some point. Thus voltages are referenced to some common (ground) point as either positive or negative (with respect to ground).
The polarity determines only the direction of current flow, the amount of current is determined by the voltage.
Thus +1V across a given resistor generates as much current as -1V. It's only the current direction that changes.
Another example is a battery. One terminal is labeled positive and one terminal is labeled negative, but that is only with respect to the other terminal.
If you connect the negative terminal to ground then you have a positive voltage from the positive terminal to ground.
If you connect the positive terminal to ground then you have a negative voltage from the negative terminal to ground.
That's how a plus and minus supply can be made.
One example of a low current MOSFET switch is a CMOS CD4066 IC.
For a higher current switch you can connect two MOSFETs together in series, source-to-source.
That will block the voltage in both directions when the gate-source voltage is 0V and conduct when the gate-source voltage is high (10V for a typical MOSFET).