Muslim house without spirit house

All Thai houses have a small spirit house in the front garden or on a place where the shadow of the house does not fall on the spirit house. The spirit house is normally in the form of a miniature house or temple, and is mounted on a pillar or on a dais.
But not so on muslim houses, the Islam forbids to believe in ghosts and the muslims don't fix spirit houses as its normally Thai tradition to have one.
Inconsistent with the believe only in Allah, all muslim people I know and I met are scared about ghosts in their mind and live the whole life with the trespass number one which says not to believe in something else than Allah.