8:31 AM PT — We asked Spencer if he has ever lived in the trailer, and he said no, adding, “I have never told anyone I lived there.” However, in the campaign ad, he says squarely, “This is where I live” as he stood in front of the trailer.

Spencer Pratt has gained traction in his campaign for L.A. Mayor by showing what he says Karen Bass did to his family — forcing them to live in a trailer after his home burned down. But TMZ has learned … he’s traded in the trailer for one of the swankiest hotels in L.A. … but Spencer says he was forced to ditch the trailer because of death threats.

Sources with direct knowledge tell TMZ … Spencer has been staying at the Hotel Bel-Air for more than a month. We’re also told his wife, Heidi, and their kids are staying in Carpinteria, just north of L.A. So the trailer is sitting lonely.

As for the Hotel Bel-Air … it’s about as luxurious as it gets. You can’t get a room for less than $1,500 a night. And check out the Swan Lake Suite — which goes for $8,090 a night.

The Hotel is decked out with a swimming pool, plunge pools, spa, restaurants, tennis courts — the works.

As you know, Spencer’s home burned down during the L.A. fires last year, after there were multiple City failures … from a lack of water to a hundred fire trucks that were sitting out of service.

As for why Spencer traded his Airstream for the Bel-Air … Spencer tells TMZ he’s been getting death threats and he’s staying at the hotel because it has “its own armed security [and] that has become the only option.”

Spencer tells TMZ, “The reality is the Bassholes and Ramaniacs are a little bit whacko, and since I destroyed them in the debate, and am surging in the polls, they are getting increasingly desperate and hostile.”