Issues with attachInterrupt

There is a wire connected to the Arduino Uno at pin2. I have a DC power supply(set to just slightly under 5V) which is connected to this wire. When i have the program running without the else if statement(just setting the output pin to HIGH, instead of HIGH and LOW), and i turn on the supply the program works as expected(So noise isn't what's triggering that pin). This is provided that I give the interrupt a significant delay time(in which case it would still be in the interrupt if bouncing is occuring).

int scanPin = 2;

volatile int outInter = 9;

void setup() {
  
  Serial.begin(9600);

  pinMode(scanPin, INPUT); 
  pinMode(outInter, OUTPUT);  
  
  attachInterrupt(0, interFunc,CHANGE);

}

void interFunc(){

  //if(digitalRead(scanPin)==HIGH){
    
    for(int i=0; i<1000; i++)
  {delayMicroseconds(3000);}
  
 // digitalWrite(outInter, HIGH);}
  
 // else if(digitalRead(scanPin)==LOW){
  
   // for(int i=0; i<1000; i++)
  //{delayMicroseconds(16);}
  
  digitalWrite(outInter, HIGH);
 // }
  
}

void loop() {
 
}