You know you've got a problem when the door speakers go 'pleased to be of service' and swoosh open with a contented sigh.

Demonic behaviours in automatic doors... This is fertile soil:

• Unlocking and immediately re-locking just as you put your key down and push the door handle;
• Sounding the 'open' tone after someone's gone through, so you *think* you don't need the key;
• Spontaneously unlocking and swinging open on a draughty day;
• Unlocking every other door in the corridor eaxcept the one you keyed;
• Intermittent 'open' tone, with random noncorrelated 'unlocked' status;
• Unlocking and blowing open in your face;
• Replacing the 'open' tone with static and faint sounds of distorted voices chanting *something* backwards;

You know, there's a lot of material to be written about hauntings & possession of familiar household and office furnishings and fixtures.