Anyone help identify old episode of Twilight Zone? or possibly Outer Limits?

Saw it circa 1966-70 on B&W TV. Setting is a century old multi-floored library. A present-day female gets so wrapped-up reading a book about a murder which occurred there 100 years ago, she gets accidently locked-in. It's dark, she can't get out, and is soon stalked by a rough-looking man who coincidently fits not only the description of the murderer in the book, but also the circumstances. Panicky, she leans out an upper window, yelling desperately for help.
I think it's the closing scene image that has stuck in my mind. You hear her screams echoing into the stillness of a quiet, dark, foggy Nineteenth-Century street below!
"Please! Help!!"
I've never figured it out - what show and episode was this?

Thanks, I'm combing the TZ Museum now... wasn't in the 1st season...

I tried to find this for you yesterday when you posted the question, but couldn't. However, I can give you the websites that I found anyhow, (if you haven't already checked those) and maybe you'll be able to find it. Not remembering the episode myself, it's harder for me. So here you go:

http://www.twilightzonemuseum.com

http://www.theouterlimits.com

Hope you find it! Good luck :-)

i've seen almost every episode of twilight zone and i don't think its that, must b outer limits