Motion sensor is one of the tools you can buy in Phasmophobia after you’ve reached a certain level.
As the name suggests, it is used to detect motion and in this case, the ghost’s movement.
Here’s how you can use a motion sensor in Phasmophobia.
Purchase a motion sensor
You’ll either need your teammate or your friend to buy a motion sensor if you can’t afford it or you haven’t unlocked it yet.
It costs 100 dollars each, so if you’ve bought it, try not to die.
How to use a motion sensor
Before placing the motion sensor, you should first identify the ghost’s whereabouts.
Once you’ve found the area / room where the ghost is, place the motion sensor on the wall nearby.
You might want to place it slightly lower by crouching, as you may sometimes encounter a child ghost.
After placing it, you will know that the ghost has passed by if the light turns green.
However, it also detects your friend’s movement, so if there isn’t anybody nearby then the ghost should be there.
Apart from that, you can also look at the motion sensor from the van. Inside the van, you can find the real-time map of the house / building and the motion sensor will be shown there.
If it turns green inside the map, then the ghost has appeared there, unless of course your friend was the one who passed the area.