How to Control 2 Fans by Using 1 Switch?

One switch (unless it is a complex one) can control (and that too On/OFF) of one outlet point.

It really does not matter how many loads are connected on that outlet point, provided the nett load does not exceed the switch rating. And all of them will be simultaneously controlled.

This is assuming you are using a simple switch.

What kind of switch/control do you have/want?

SPST, SPDT, DPST, DPDT, ....?

http://en.wikipedia.org/wiki/Switch

FAN 1 = X

FAN 2 = Y

SWICH= Z

0 = FAN OFF

1 = FAN ON

-----------

Z X Y

0 0 0

1 1 0

1 0 1

0 1 0

0 0 1

1 1 1

I think that's all the possible combinations. Good luck.

Or did you mean "how" as in practical?