Under the bed or out of the wardrobem maybe? One particularly nasty one that I had when a child used to climb up the drainpipe and peek through any gaps in the curtains.
Fungus the Bogeyman in the Raymond Briggs book comes out of the subterranean world of Bogeydom, if I remember correctly. I wasn't being funny with the first answer (I rarely am) but the Fungus reference only clicked after I'd posted.
When I was a kid, I used to think he climbed up the drainpipe and up through the toilet ! Mind you I used to think , with a child's logic that Father Christmas also got in like that as all our fireplaces were blocked up !
He was under my bed, but he was a kind bogeyman because when I wanted to wee, he would give me '10' to get to the toilet before he got me and then '10' to get back and into bed. Trouble is, if you misjudged it, you would start panicking becuase your mind was counting down and you could see the bogeyman starting to smile and rub his hands together, but your body was going into spasms and your feet were running on the spot like in a flippin' cartoon! God it was scary!
oh dmsjps I am laughing so much, the bogeyman in my room used to give me a time limit before he got me. Thankfully I always made it. I am now nearly 40 and if I go to the loo in the night as soon as I flush the chain, I run like a bat out of hell back to bed. I still daren't sleep with any of my feet or hands hanging out of the side of the bed just in case - you never know