ph sensor fluctuates from 0 to 800 in yogurt

Hello amazing people I m damn ashamed to share a simple but ridiculous issue of my pH sensor..... I m usin NodeMCU and am tryna read voltage at first..........when left un toucher it fluctuates as well as in water or in any thing......here is ma code (Behold! Thy lord Casted a Big and long Code onto Thee)

void setup() {
  Serial.begin(9600);
}
void loop() {
    Serial.println(analogRead(A0));
}

heres the sensor https://www.google.com/search?q=ph+sensor+not+working+arduino&rlz=1C1CHZL_enIN780IN780&source=lnms&tbm=isch&sa=X&sqi=2&ved=0ahUKEwjCoZvjpLnfAhVak3AKHZ0UAlkQ_AUIDygC&biw=1242&bih=569#imgrc=GVnLQp1NXHASJM:

Please post a link to the actual sensor, not to a google search.

The symptoms you report suggest a floating input.

Thanks jremington for your reply…even i thought these are floating valued…so i wrote A0 to high,then values were different but still fluctuating

Writing a HIGH to A0 turns on the pullup resistor, which will lead to wrong readings in any case.

To avoid a floating input, connect the pH meter and Arduino grounds. If you have already done that, you probably have a faulty connection.

Post a hand-drawn (not Fritzing) diagram showing all the wiring.