Hi, just wanna give my contribution to the community.
Following is the serial gateway code with support of auto ID, which is still missing in the latest of MySensor (1.4) library (CMIIW).

links : bitbucket

@Fredrik-Carlsson info you havent got one, please check my development git

• Pulse sensor ( Watt, KWh and Ampere )
  {
  "id": "EnergySensor,
  "name": "Energy Sensor",
  "class": "MySensorsPulseMeter",
  "nodeid": 3,
  "batterySensor": true,
  "sensorid": 1,
  "appliedVoltage" : 220
  }

Hi @ericvdb , you can use multi tester like in this link....

@Tibus my suggestion is that try other nrf radio.
Right now I can low as 10uA while sleeping

@Tibus do you have other nrf to try? I'm affraid you're using fake nrf.
30% of my nrf (out of 10), are fake...

one more thing, sleep method in above post dont turn off nrf radio while sleep.
you can try gw.sleep() if you want turn off nrf radio while sleep (MyGateway gw)

@iask how is the result?

@iask I haven't upload my latest door sketch to my node yet. But if I'm using above sketch, idle 4uA and around 18mA while transfer.

Do you have any issues like me before?

@Fredrik-Carlsson please try it, please notice me if you find any bugs.
I'm in the middle of pull request to @Dheeraj

@Fredrik-Carlsson info you havent got one, please check my development git

• Pulse sensor ( Watt, KWh and Ampere )
  {
  "id": "EnergySensor,
  "name": "Energy Sensor",
  "class": "MySensorsPulseMeter",
  "nodeid": 3,
  "batterySensor": true,
  "sensorid": 1,
  "appliedVoltage" : 220
  }

@mainali have you finished the sketch? do you mind to share?

@mainali I think @ferpando solution is quite nice. He add RF switch to existing button. @ferpando could we track physical switch state using this?

@AWI yes, it can communicate with the gateway normally.
Following is my test result

1. First code

/**
 */
#include <SPI.h>
#include <MySensor.h>  
#include <avr/sleep.h>
//#include <avr/wdt.h>

MySensor gw;

// watchdog interrupt
//ISR (WDT_vect) { wdt_disable();  /* disable watchdog*/ }  // end of WDT_vect

void setup()  
{ 
//  pinMode(7,OUTPUT);
//  digitalWrite(7, HIGH);
//    gw.begin();
  Serial.begin(115200);
  Serial.print("Setup");
}

void loop()      
{  
//  gw.powerUp();
  //digitalWrite(7, HIGH);
//  gw.sendBatteryLevel(0);  
  Serial.print("Loop");  
  Serial.flush();
//  gw.powerDown();
  //gw.sleep(30*1000);
  sleep();
//  digitalWrite(7, LOW);
//  sleep();
}

void sleep(){
   // disable ADC
  ADCSRA = 0;  

  // clear various "reset" flags
  MCUSR = 0;     
  // allow changes, disable reset
  WDTCSR = bit (WDCE) | bit (WDE);
  // set interrupt mode and an interval 
  WDTCSR = bit (WDIE) | bit (WDP3) | bit (WDP0);    // set WDIE, and 1 second delay
  wdt_reset();  // pat the dog
  
  set_sleep_mode (SLEEP_MODE_PWR_DOWN);  
  noInterrupts ();           // timed sequence follows
  sleep_enable();
 
  // turn off brown-out enable in software
  MCUCR = bit (BODS) | bit (BODSE);
  MCUCR = bit (BODS); 
  interrupts ();             // guarantees next instruction executed
  sleep_cpu ();  
  
  // cancel sleep as a precaution
  sleep_disable();
}

With this code I've got

1. Test_Current_0 : 0.004 mA - Plain, Just Arduino (w/o LED, w/o Voltage Regulator)
2. Test_Current_0 : 0,009 mA - Config in point 1 + Voltage Regulator (HT7333)
3. Test_Current_0 : 1,58 mA - Config in point 2 + NRF24L01+

Another test

/**
 */
#include <SPI.h>
#include <MySensor.h>  
#include <avr/sleep.h>
//#include <avr/wdt.h>

MySensor gw;

// watchdog interrupt
//ISR (WDT_vect) { wdt_disable();  /* disable watchdog*/ }  // end of WDT_vect

void setup()  
{ 
//  pinMode(7,OUTPUT);
//  digitalWrite(7, HIGH);
  gw.begin();
  Serial.begin(115200);
  Serial.print("Setup");
}

void loop()      
{  
  //gw.powerUp();
  //digitalWrite(7, HIGH);
  gw.sendBatteryLevel(0);  
  Serial.print("Loop");  
  Serial.flush();
  //gw.powerDown();
  gw.sleep(30*1000);
  //sleep();
//  digitalWrite(7, LOW);
//  sleep();
}

void sleep(){
   // disable ADC
  ADCSRA = 0;  

  // clear various "reset" flags
  MCUSR = 0;     
  // allow changes, disable reset
  WDTCSR = bit (WDCE) | bit (WDE);
  // set interrupt mode and an interval 
  WDTCSR = bit (WDIE) | bit (WDP3) | bit (WDP0);    // set WDIE, and 1 second delay
  wdt_reset();  // pat the dog
  
  set_sleep_mode (SLEEP_MODE_PWR_DOWN);  
  noInterrupts ();           // timed sequence follows
  sleep_enable();
 
  // turn off brown-out enable in software
  MCUCR = bit (BODS) | bit (BODSE);
  MCUCR = bit (BODS); 
  interrupts ();             // guarantees next instruction executed
  sleep_cpu ();  
  
  // cancel sleep as a precaution
  sleep_disable();
}

Config is the same with no 3 (above), but the power consumption in sleep I take around 2.37 mA.

Is it maybe I've got bad NRF24L01+ ?

----- Updated
It seems my suspicion, it seems the cause of high power consumption is NRF24L01+ radio. I've checked all of my radio, it appears that 2 of 9 seems fake / bad condition.

Thanks for contribution of @HarryDutch @AWI @Dheeraj @tbowmo @GuyP and others, so now I can play with other level of MySensor.

Thanks