  Blue straggler stars (BSSs) are formed through mass transfer or mergers in
binaries. The recent detections of white dwarf (WD) companions to BSSs in M67
suggested a mass transfer pathway of formation. In search of a close companion
to five BSSs in M67 that are known to be spectroscopic binaries, we study the
light curves from K2 and TESS data. We use PHOEBE to analyse the light curves
and estimate the properties of the companions. We detect variability in WOCS
1007, and the light curve is dominated by ellipsoidal variation. Using the
light curve and radial velocity measurements, we estimate its orbital period to
be 4.212$\pm$0.041 d and $e$ = 0.206$\pm$002. The mass of the companion is
estimated to be 0.22$\pm$0.05 M$_{\odot}$ with a radius of 0.078$\pm$0.027
R$_{\odot}$, confirming it to be a low mass WD with T$_{\rm eff}$ =
14300$\pm$1100 K. The estimated mass of the BSS, 1.95$\pm$0.26 M$_{\odot}$, is
similar to that estimated from isochrones. The BSS in WOCS 1007 shows $\delta$
Scuti pulsations, although it is slightly deformed and likely to be formed
through an efficient mass transfer. Though we detect a light curve for WOCS
4003 showing grazing eclipse with ellipsoidal variation, the estimated
parameters are inconclusive. Apart from the 0.44 d period, we found smaller
eclipses with a period of 1.1 d, suggesting a compact triple system. In the
case of WOCS 4003, WOCS 5005, and WOCS 1025, no eclipses or pulsations are
detected, confirming the absence of any short-period inner binary with high
inclination in these BSSs.
