I've searched (And maybe I should have searched harder, hope not...) But I've not found a thread about weird glitches, and bugs founds in game that can be quite... Creepy.
I'll start :)
I was playing Half Life 2 Episode 2 a couple of yeas ago, and was in that part where you have a car and can basically drive about in a forest... I noticed this strange house giving strange light pulses and decided to investigate... After a (Quite broken) cutscene I was confronted with this ghostly image...
According to walk-throughs he should be dead... But no, He just stands there staring at you no mater where you go with a scary fuzziness to his face, somewhat resembling photographs in that movie The Ring.
I know it's just a bug.. But eh, creeped me out, ha.
(https://www.susans.org/proxy.php?request=http%3A%2F%2Fs18.postimg.org%2F6xqg0736t%2FDUDE_A_GHOST_IN_HL2_E2.jpg&hash=220e428f63f038c1cbb9d41a719718e6470dab6e) (http://postimg.org/image/6xqg0736t/)
Any other stramge experiences? :D