I haven't seen ghosts per se. But I did see "shadows" in the shape of people that ran around. I've also seen objects move by themselves (glasses moving on tables, trash can lids violently moving, banging). Spirits tend to visit my dreams. Especially when I am extremely stressed.
Most of the time they aren't very friendly looking. lol.
I can totally relate to you feeling that negative energy in the hotel. When I walk into a place with lots of negative energy it feels so heavy. It saps the energy right out of me, like walking through mud. I can't stay in a place like that very long because it's filled with psychic vampires.
Black tourmaline helps with keeping the negative energy off. I carry one everywhere I go. Burning sage takes the heaviness away from an area. I am not telling you that you should do these things, but I'm just relaying my experience just in case you want to give it a shot.
"In fighting and in everyday life you should be determined though calm. Meet the situation without tenseness yet not recklessly, your spirit settled yet unbiased. An elevated spirit is weak and a low spirit is weak. Do not let the enemy see your spirit.” - Miyamoto Musashi