Spencer Pratt Staying at Bel Air Hotel, Not Airstream Trailer (opens in new tab)

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.