In linux OR OSX you can point to the wallet file using the -w tag
./electrum -w PATH/TO/WALLET_FILE
Enter this in Terminal if you are using the Mac App
cd /Applications/Electrum.app/Contents/MacOS
./electrum -w (drag the wallet file here)
This appears to be a one time solution - you have to open Electrum this way through terminal everytime if you want to store your wallet file somewhere other than the hidden .electrum folder in user's home directory. Is there a way to point the program to a wallet file in another location permanently in Mac OS (10.11.4 El Capitan)?