Step 1: Things You Will Need

Arduino
Relay module(4 channel)
HC 05 Bluetooth module
Servo motor
Sonoff smart switch
5V Relay(1 channel)
5V Relay(2 channel)
Breadboard
Leaf switches
Geared dc motor
Diodes
Lock (12V)
Wheel
Extension box
Ice cream sticks
Hot glue gun
Wires

Step 2: Let's Start

connect the relay module to your Arduino (to pin 2,3,4,5) as shown in the circuit
modify your extension box and connect (SONOFF) smart switch as shown in the circuit and picture
modify the wiring of your room light as shown in the circuit
connect the light and extension box to relay module as shown in the circuit
connect the servo to the fan regulator as shown in the picture
connect the servo to Arduino (to pin 6) and if needed (put a relay in between the circuit of the servo), I have put the relay because my servo vibrates whenever it's powered so I thought because of continuous vibration there may be an issue with the servo
connect the relay of the servo to Arduino (to pin 7)
the circuit which is in the bottom right corner is of automating the window the two switches are the leaf switch and (L) is the lock and (M) is the motor
first get all the things fixed to the window
you can use sandpaper to increase friction between the motor wheel and window
you can make a structure with ice cream sticks to place the motor as shown in the picture
and also place the lock so that it can lock the window from one side
connect the relay as shown in the picture
use a 12V adapter to power the motor and lock
connect the relay to Arduino (to pin 8)
I have connected mosquito repellent, 12V adapter(for window) and laptop charger to pin 4,3 and 2 in extension box respectively

Step 3: Programing the Arduino

<p>#include   //Load the servo Library</p>Servo myPointer;
int relay[]={2,3,4,5};
int Relay[]={7};
int RElay[]={8,9};
int servoPin=6;
int w=5000;
int tt=0;
int t=2000;
int ch=4;
int i=0;
int j=1; 
int k=2;
int l=3;
int m=0;
int n=0;
int o=1;
int zero=10;
int first=32;
int second=58;
int third=86;
int fourth=114;
int fifth=138;<p>void setup() 
{ 
  Serial.begin(9600);
  myPointer.attach(servoPin);
  pinMode(relay[i],OUTPUT);
  digitalWrite(relay[i],HIGH);
  pinMode(relay[j],OUTPUT);
  digitalWrite(relay[j],HIGH);
  pinMode(relay[k],OUTPUT);
  digitalWrite(relay[k],HIGH);
  pinMode(relay[l],OUTPUT);
  digitalWrite(relay[l],HIGH);
  pinMode(Relay[m],OUTPUT);
  digitalWrite(Relay[m],HIGH);
  pinMode(RElay[n],OUTPUT);
  digitalWrite(RElay[n],HIGH);
  pinMode(RElay[o],OUTPUT);
  digitalWrite(RElay[o],HIGH);
} 
 
 
void loop() {
 if(Serial.available())
 {
   String value = Serial.readStringUntil('\n');
   Serial.println(value);
   if(value == "0")
   {
     digitalWrite(Relay[m],LOW);
     delay(tt);
     myPointer.write(zero);
     delay(t);
     digitalWrite(Relay[m],HIGH);
   }
   if(value == "1")
   {
     digitalWrite(Relay[m],LOW);
     delay(tt);
     myPointer.write(first);
     delay(t);
     digitalWrite(Relay[m],HIGH);
   }
   if(value == "2")
   {
     digitalWrite(Relay[m],LOW);
     delay(tt);
     myPointer.write(second);
     delay(t);
     digitalWrite(Relay[m],HIGH);
   }
   if(value == "3")
   {
     digitalWrite(Relay[m],LOW);
     delay(tt);
     myPointer.write(third);
     delay(t);
     digitalWrite(Relay[m],HIGH);
   }
   if(value == "4")
   {
     digitalWrite(Relay[m],LOW);
     delay(tt);
     myPointer.write(fourth);
     delay(t);
     digitalWrite(Relay[m],HIGH);
   }
   if(value == "5")
   {
     digitalWrite(Relay[m],LOW);
     delay(tt);
     myPointer.write(fifth);
     delay(t);
     digitalWrite(Relay[m],HIGH);
   }
    if(value == "switch on mosquito repellent")
   {
     digitalWrite(relay[i],LOW);
   }
   if(value == "switch off mosquito repellent")
   {
     digitalWrite(relay[i],HIGH);
   }
    if(value == "start charging laptop")
   {
     digitalWrite(relay[k],LOW);
   }
   if(value == "stop charging laptop")
   {
     digitalWrite(relay[k],HIGH);
   }
    if(value == "lights on")
   {
     digitalWrite(relay[l],LOW);
   }
   if(value == "lights off")
   {
     digitalWrite(relay[l],HIGH);
   }
   if(value == "open")
   {
    digitalWrite(relay[j],LOW); 
    digitalWrite(RElay[n],LOW);
    digitalWrite(RElay[o],LOW);
    delay(w);
    digitalWrite(RElay[n],HIGH);
    digitalWrite(RElay[o],HIGH);
    digitalWrite(relay[j],HIGH);
   }
   if(value == "close")
   {
    digitalWrite(relay[j],LOW); 
    digitalWrite(RElay[n],HIGH);
    digitalWrite(RElay[o],HIGH);
    delay(w);
    digitalWrite(relay[j],HIGH);
   }
   if(value == "switch on everything")
   {
     digitalWrite(relay[i],LOW);
     digitalWrite(relay[k],LOW);
     digitalWrite(relay[l],LOW);
   }
   if(value == "switch off everything")
   {
     digitalWrite(relay[i],HIGH);
     digitalWrite(relay[k],HIGH);
     digitalWrite(relay[l],HIGH);
   }
   if(value == "good night")
   {
     digitalWrite(relay[k],HIGH);
     digitalWrite(relay[i],LOW);
     digitalWrite(relay[l],HIGH);
     digitalWrite(relay[j],LOW); 
     digitalWrite(RElay[n],HIGH);
     digitalWrite(RElay[o],HIGH);
     delay(w);
     digitalWrite(relay[j],HIGH);
   }
 }
}</p>

This is the code for Arduino

upload the code to Arduino
connect the (HC-05) Bluetooth module to Arduino (RX to pin 1 and TX to pin 0) let the pin STATE and EN be empty
always upload the program by unplugging TX and RX pins of Bluetooth module

Step 4: Let's See How Does It Work

Take your smartphone open play store
download the eWeLink app to control Sonoff switch
download Bluetooth Terminal (by Juan Sebastian Ochoa Zambrano)
open ewelink use a wifi router or any wifi source to pair the smart switch
switch on the Arduino
open the Bluetooth settings and pair with your Bluetooth module password will be 1234 or 0000
now to switch on lights type lights on
to switch off lights type lights off
to switch on mosquito repellent type switch on mosquito repellent
to switch off mosquito repellent type switch off mosquito repellent
to switch on laptop charger type start charging laptop
to switch off laptop charger type stop charging laptop
to adjust the speed of fan type 0(off), 1, 2, 3, 4 or 5
to open and close the window type open and close respectively
you can have a look at the video so that it will be cleared
if u have any better ideas you can put it in the comments