Ummm, EMF = electromotive force. This is just the proper term for "voltage" in a circuit. It is the "E" in Ohm's Law ("E = IR" or voltage = current x resistance). This voltage is what is running through wires. While it is also used in inductors and transformers as electromagnetic induction, these components are generally shielded to prevent spurious signals or magnetic radiation from "entering" the circuit from the outside and from radiating out too as that would indicate an inefficient loss of power. Not to mention the FCC and other regulatory agencies frown on unwanted EMI/RFI emanations.
Surely you have much more than what a router utilizes running through the walls next to your head powering the HVAC, TVs, lights, kitchen appliances and more - especially in an apartment complex.
If you meant RF energy, if a worry, I would be much more concerned about holding your cell phone right next to your head than what emanates in an omnidirectional pattern from a wireless router several feet away. From a single "smart" cell phone, you have RF radiation from the cell network, wifi, Blu-tooth, and NFC. 
With your wireless router, you typically can set access times in the admin menu too - that is, you can disable the wifi side while you sleep. Then you only need to worry about sitting 2 feet away from your computer's wifi adapter for hours on end. :roll eyes (sarcasti
Note that many of these wireless router/residential gateway devices have mounting holes on the back to "hang" the unit off the wall with 2 small screws. This will get the device off the floor and the cardboard boxes out of the room. You can hang it up as high as the power cord will allow which would hopefully improve propagation.
