How to use a SE-10 pir sensor to control a lamp


I am a newbie of the Arduino context and i am experiencing the potentiality of this project. I thought to implement a lamp controller using a relay module and a pir sensor. I bought from the following parts: SE-10 pir sensor and DFRobot relay module. The pir sensor works well if I try to blink a led, but I have a lot of problem with the control of the lamp. The lamp turns on when the sketch detects a motion and turns off after an inactivity period, obviously. After turning off the lamp I notice a strange behavior of the sensor. In fact, the sensor detects motion for some time. How I can avoid this unwanted behavior? Thanks for your interest.

If the PIR sensor can see the lamp and its tungsten filament lamp then this is normal - you are changing the amount of IR falling on the sensor by large amounts. You can program the sketch to be insensitive for a few seconds after lamp switching...

I removed the power supply at the lamp and I have seen the same behaviour. So I think that the problem isn't the noise of the infrared but a tension problem that occurs when i turn off the relay [ digitalWrite(relayPin, HIGH/LOW) ].

I posted an attachment that is an image of my circuit scheme.