Some of the western religions have evil spirits like devils and demons. Does the concept or belief in evil spirits occur in Buddhism?
It's not always as clear as 'good' or 'evil'. Angry, vengeful spirits also exist in forms of Buddhism. Sometimes also seen as protectors, they can be a source of controversy.
More common is one's own belief in (or, more practically, fear of) something that is indefinitely, and irreparably, sinister or evil. We subscribe to all sorts of interesting notions as children, some things tend to persist. Ultimately, it's what your mind manages to trick you into into feeling; there are plenty of Christians that don't believe that demons exist so it really does depend on the individual.
So, yes to the concept (with emphasis on what neubau mentions about indigenous spirits), but belief is a little more complicated; belief coupled with a healthy dose of ambivalence can be quite common.
For children, I think the boogeyman is rather universal :)
In mainland Southeast Asia, indigenous spirits have been incorporated to a greater or lesser degree into Buddhist belief systems. I believe this is known as syncretism. In Burma these spirits are called nats, in Thailand phǐ. Thai phǐ can be benign, like house spirits, or they can be malevolent “ghosts”.
You can see a variety of Thai ghosts in this TV ad for light bulbs (the slogan is “in the bright light, no one is afraid”). The family is having a picnic within the grounds of a temple (an odd thing to do), and the father tells his son the name of each ghost. The huge emaciated type, which is called a preta or hungry ghost, you might say is more “Buddhist” than the others because it often appears in depictions of Buddhist hells. The preta’s mouth is just a tiny hole, so it can’t eat properly, which might be punishment for greed in a former life.
If it were, it would be the same as saying:
"I am a Buddhist, you are not, you do the opposite of what I do and "believe in", hence I am good and you are wrong, hence you are devil."
In my humble opinion, it is only about being able to going back to null and "see" things around as they are and those who don't (haven't).
And those who don't (haven't) are not evils, for they haven't understood and therefore they are still bind to pleasures, attachments, ego and the "I" that drive them to perform what they do. They haven't been able to "unshell" themselves from these "qualities" through compassion and dis-attachment of the aforementioned.
Thanks for question.
Yes, Buddhism has evil spirits :)
In Pali Canon, in Jatakas, and in Tibetan Buddhism poems (for example "100,000 songs of Milarepa") there are numerous references to spirits and demons, both good and evil. Many of them are metaphorical depictions of various psychological forces taking possession of a person (e.g. Mara, the spirit of doubt and confusion, that famously challenged Buddha by suggesting he wasn't really enlightened). Others are personifications of the "spirit" (energy, mood) of a certain place (e.g. a haunted forest). There are also Rakshas, (former) people so completely possessed by evil forces that they are no longer considered people, e.g. the jungle cannibals.
From modern perspective, the concept of demon is not necessarily a superstition, but more like a poetic way to talk about real phenomena taking place.
Checkout the "States of Deprivation" under the 31 planes of existence. Beings there are not necessarily evil. Rather they were born there because of evil deeds. But we do have an evil god called the Mara. He lives in the heaven called "Paranimmita-Vasavatti" Whoever holds the title 'Mara' is always evil as long as he holds that title.