If you are installing two switches, wire nut one wire from each of the switches together so the current will run through both switches which are normally closed so current can flow.
What we normally do is break the condenser (wire) which will be the stat wire attached to the copper line set leading to the condenser from the furnace/air handler. Tunr the power off to the furnace by the breaker or switch if you have one, not just stat off. You do not want to blow fuses and yes, 24 volts hurts too.
Locate one of the two wires to the condenser, either the red or the white. Red and white are most commony used but they could be any color and usually there are only two wires to the condenser. If heat pump or communicating then you need to let us know.
Break one of the two wires to the condenser as in cut it open and wire nut the one line from one of the float switches to one side (small orange or blue or gray wire nut) and wire nut the other side from the other float switch to the other. Since the float switches are are already tied together in series, the current is now going through both so if one fails (trips), either one of them, the condenser low voltage breaks which means no more refrigerant can flow so no more condensate water can be produced. If ever your system is set to cool but is blowing not cool air but just fan air and your condenser is not operating then your float switch possibly has tripped and you need to check them. Why we install switches as well as to protect from possible water damage.
Turn your breaker back on and enjoy your now more "protected" system.
Please send $90.99 to Sir Preston Aire, Internet Float Switch Diagnostic Solutions, Houston Texas, I am Your Hvac Daddy Forever and Ever Amen, 90210.
Of course you could break the actual power to the system but then you wouldn't have any air, not just not cool air.