I'm hallucinating, i can clearly see a mouse running across my lounge, but no one else can, an we have searched hi and low an found nothing, why am i seeing these things?

Seeing mice: that are not there ? ( this is not an uncommon complaint in those who take medications / agents that affect dopamine levels in the brain. ) also occurs in some people with partial complex and partial elementary seizures. Might want to consult with a neurologist if the cause is not obvious ( medication, rye mold, or a house cat that has become indifferent )