Safety razors with disposable blades were introduced about 120 years ago, at one blade a day that's a bit less than 45000 blades
Double edged blades dimensions are: 0.1mm x 42.7mm x 22mm for 98.21mm³
45 000 blades would take a volume of 4 419 450mm³ or about 270in³
A regular indoor wall is made of 2x4 and each stud is 14.5 inches apart (16 inches on center). A 2x4 is in truth 1.5" x 3.5" so each inch of height inside the wall is 3.5 x 14.5 x 1 which is 50.75in³
45 000 blades stacked perfectly would therefore use 270 / 50.75 = 5.32 inches of the wall's height... So even if they didn't stack perfectly, it's pretty safe to assume that there's enough space inside the wall for hundreds of years at one blade a day (especially since old houses usually used true 2x4 and had their studs at 24" on center)