"Burial Ground : Nights of Terror" (Italy;1981)?
This was an Italian zombie movie directed by Andrea Bianchi and like most Italian zombie movies was released in the U.S. in an English dubbed version. Here is part of the plot summary from Wikipedia:
A professor (Raimondo Barbieri), studying an Etruscan crypt near a grand mansion, accidentally unleashes an evil curse. The curse reanimates the dead buried in the area and the zombies devour the professor. Three jet-set couples and the creepy, mentally challenged son of one of the women arrive at the mansion at the professor's invitation. The guests are quickly attacked by rotting corpses as they begin rising from their graves.
The group of people lock themselves in the mansion and, as night falls, the zombie siege begins. The first victim is Kathryn, the maid (Anna Valente), who is pinned to a window and decapitated with a scythe. The zombies then begin to display unusually high levels of intelligence, using tools, axes to chop through doors, etc. One of the guests, George (Roberto Caporali) tries shooting at them with a shotgun but quickly runs out of shells.
Here is an old VHS trailer from YouTube. Sorry, the quality is poor but you can see the maid getting it with the scyth at 1:25. You can also watch the entire movie on YouTube.
WARNING:GRAPHIC ZOMBIE GORE!