Name changed because I've told this in real life.
And it still gives me chills to recount it.
When my now 12 year old was almost 3 I moved him to his own bedroom. It had been used as a storage room but I decorated it all lovely for him. I did have prickly feelings in certain parts of the house and I could swear the toilet had flushed without anyone else in the house before but I dismissed it as being sleep deprived with little ones.
Without fail he woke up screaming in terror at the same time every night. He would say things like "I don't like the man!!" And "tell that man to stop it!" I was told it was night terrors and to do that monster spray trick etc, but it was still the same. Eventually he started refusing to even play in there during the day, calling the man Barney and saying he kept frightening him. If he walked past the room and the door was open he would freeze like he'd heard something terrible and come flying at me with his heart pounding, begging me to close the door.
I let him sleep in my bed for weeks and weeks and he would sleep right through and seemed to forget about Barney. One night, I had a stinking cold and couldn't get comfy with his little elbows rammed into me, so I gently lifted him into his bed.
Like an alarm set for the exact time, he woke up screaming in absolute terror. If you've ever heard real, desperate terror, it's a sound that chills your blood. I ran to him and he was standing up on his bed, his eyes were huge and just wild looking and he practically climbed up my body clawing at my skin and sobbing so hard. I said "Oh, baby, what's the matter??" He replied and said "Barney!! He touched my face!!"
Trying to calm him, but also out of fear I firmly said "Go away, Barney!!" And my little boy grabbed my cheeks and looked right into my eyes and between sobs said "Mummy, Barney can't go away. He walks in the walls."
Although this sounds like a horror story, it was very real and we actually moved house as soon as possible because of it. The people who moved in after us didn't stay long and said it was "a creepy place."