I found red wax in the keyhole on my front door. Any idea ?

I found red wax in the keyhole on my front door.I don’t have anything on my key that would do this, but I did notice some on the tip after I took the key out when locking up this morning. A little concerned that someone may have been messing with my lock last night.

Answer: “Careful! It’s a method used by squatters/burglars to see who on the block is using their key or even if there might be empty homes.”