index.js

var lightwallet = require('eth-lightwallet')
var password = ''
var seedPhrase = "fatal already jacket nose acid young shuffle gaze angry always copper huge"
var hdPathString = "m/44'/60'/0'/0"
var msg = "this is a message";

// verify here:
// https://www.myetherwallet.com/signmsg.html
var signatureFromMyEtherWallet = 
{
  "address": "0x3b707395830a4ab37832224375b663054df2ac1d",
  "msg": "this is a message",
  "sig": "0xd8557b1633b144ad6175896f7fd149928bcc2b6185811789029509d627b167a641840fabf137aa802e78f3c402f13cdb143595dbcfc855734f766f9a9ef90eb11b",
  "version": "2"
}

lightwallet.keystore.createVault({
  password: password,
  seedPhrase: seedPhrase,
  hdPathString: hdPathString
}, function (err, ks) {
  ks.keyFromPassword(password, (err, pw) => {
    ks.generateNewAddress(pw)
    var addr = ks.getAddresses()[0]
    var signedMsg = lightwallet.signing.signMsg(ks, pw, msg, addr)
    var signedHex = lightwallet.signing.concatSig(signedMsg)
    var signatureFromEthLightWallet = {
      "address": addr,
      "msg": msg,
      "sig": signedHex
    }
    console.log( signatureFromMyEtherWallet )
    console.log( '--------------------------' )
    console.log( signatureFromEthLightWallet )
  })
})

node index.js
{ address: '0x3b707395830a4ab37832224375b663054df2ac1d',
  msg: 'this is a message',
  sig: '0xd8557b1633b144ad6175896f7fd149928bcc2b6185811789029509d627b167a641840fabf137aa802e78f3c402f13cdb143595dbcfc855734f766f9a9ef90eb11b',
  version: '2' }
--------------------------
{ address: '0x3b707395830a4ab37832224375b663054df2ac1d',
  msg: 'this is a message',
  sig: '0xa286da0caf90870d349e35b33c0404ba7a52996af7a86bac47ccc335e6ac71a34b2e2adc7f6a23aa875bc7187e0952a4974a85792aedc2d0973b1346bc942b381c' }