I have successfully filled the hole first by pushing the wall paper covering in with the handle end of a screwdriver as indicated above. I then take a dab of latex caulk (white, antique white, or almond depending on Wall color) and then smooth over with finger. This usually hides the holes fairly well.
Steve Rinker
Rochester, NY
2013 Keystone Sydney 340FBH 5th Wheel, 12,280 lbs loaded (scale)
2015.5 GMC Sierra Denali 3500, SRW, Duramax, CC, Payload 3,700 (sticker- not scaled yet)
Take my posts for what they are, opinions based on my own experiences.