I need advice on how to get rid of an unwanted roommate

I need some help here.

It all started this morning. That's when I realized there was somebody else in my apartment.

I've had shady landlords before, who had rented out my spare room without permission. I know that sounds unbelievable to most of you, but it happened. Over ten years ago when I lived near a college in a house I rented with three friends.

We just woke up one morning and there was some guy living in the spare room who I'd never met before. The space we were using as our living room on the main floor - it was no longer ours. It was this guy's bedroom now.

But that was a college house with a creepy landlord who violated every rule in the book.

The apartment I own now was supposed to be mine.

I've lived here for five years and I've never had a problem.

But this morning, around 3:00 AM, I felt like someone was watching me. Then I looked and saw the shadow of a person in my hallway. And their feet were sticking out - only the points of their long toes - dressed in black leather shoes.

My heart skipped a beat and I was freaked out to say the least.

"Who the hell are you? How did you get in here?" I yelled.

I stood up and when I did the shoes slipped out of view momentarily.

When I went to look and see who was in my hallway, it was empty. But a cold spot was in the air, like a breeze was coming in through a window, except they were all closed.

I looked in my spare room and my bathroom, then checked behind the shower curtain.

Nobody was there.

My cat jumped into the tub when she saw me looking in there. She loves to play in the tub for some reason.

Her paws made echoing sounds as she raced around on the porcelain and mewed at me, wanting me to play with her.

I went to sleep a little while after that, feeling satisfied that my apartment was empty and I had just imagined the shoes in the hallway and the shadow of a man watching me from the corridor.

When I woke up in the daytime it all seemed like a bad dream, and I thought about how silly it had been for me to think there was someone else in my apartment.

Now that it's night again, though, it's a different story.

I'm terrified.

I'm in the bathroom and I heard my cat in the tub, moving around behind the curtain.

But as I reached my hand behind the shower curtain to stroke her fur, I felt her body press up against my leg instead.

The cat was on the floor beside me. Not in the bathtub.

That's when I heard a man clear his throat on the other side of the shower curtain.

What the hell do I do about this unwanted tenant?